Every television season produces its share of trends. Here are five that caught my eye.

1. The rise of serialized drama.

Not too long ago, serialized programs couldn’t get arrested on the broadcast networks. “We’re faced with two very large, looming presences on TV now, which are reality and the procedurals” such as the various “CSIs” and “Law & Orders,” “The 4400” executive producer Ira Steven Behr told the Tribune in March 2004.

Thanks to the syndication success and endless repeatability of self-contained procedurals and dramas that only timidly dipped into ongoing story lines, fans of challenging, strongly serialized programs - such as Joss Whedon’s “Angel,” the cancellation of which prompted the article mentioned above - often had to go to the cable networks for that kind of intensely serialized, character-driven fare.

Still, as other producers noted in the piece, TV is a cyclical beast, and lo and behond, six months after the publication of that article, a little show called “Lost” debuted. And now the broadcast networks can’t seem to get enough of dramas that have season-long plots, extended character arcs and even genre elements.

“Jericho,” “Heroes,” “The Nine,” “Six Degrees,” “Runaway” “Kidnapped” and “Vanished” are just some of the shows that will depend to a large degree, as “Prison Break,” “24” and “Lost” do, on viewers who are not only willing but anxious to watch those shows week in and week out.

“I think we got in under the wire, and I do think we’d have a tougher time coming up against [fall’s] real glut of serialized dramas,” says Matt Olmstead, an executive producer for “Prison Break,” a serial that debuted a year ago. “We’re very glad that we premiered when we did.”

As well he should: Last year, “Prison Break” stood out; this year, it’s the template. But the fact that the broadcast networks are throwing out so many serialized shows this fall should prompt viewers to toss these questions right back: How much time do you people at the networks think we have, even if we can get our DVRs to work overtime? And why the heck should we trust the networks that have burned us so many times by canceling serialized shows after we’d gotten addicted to them?

And when those unlucky shows do get canceled, critics will get hundreds of outraged e-mails and phone calls from readers, as we did last year when “Threshold,” “Invasion,” “Surface” and “Reunion” were canceled. Don’t network suits realize that viewers are wary of spending their precious free time on TV shows that might well leave them hanging?

Nina Tassler, the president of entertainment for CBS, glibly nixed those kinds of concerns at the Television Critics Association (TCA) press tour in July. “I don’t think audiences make a decision to commit to a show, one way or the other, based on it being serialized or not,” she said. And if viewers get hooked on a show that tantalizes them with a complicated series of questions, “in success, those questions will be answered.”

Translation: We’ll cancel the arc-heavy shows that don’t get “Lost”-style ratings, and it’s just too bad for you if your favorite serialized drama bites the dust.

Still, don’t expect the networks to give up on these kinds of shows, even when - not if - this season produces serialized casualties. The lesson of “Lost” is that fans of that kind of complicated drama will follow it wherever it goes - they’ll check out the Web sites, buy the books, buy the episodes on iTunes and in DVD form, post on the message boards and participate in an endless array of show-related activities on a wide array of new-media platforms.

“I think everyone has a limit to the number of shows they’re willing to commit to, but I also think very few people are going to decide before the season begins that they don’t have any room” on their schedule for serialized shows, said Kelly Kahl, CBS’ executive vice president for scheduling. “If people are left hanging, hopefully we’ll have the ability to stream those additional episodes and make them available on iTunes.”

2. Anti-heroes as lead characters.

If you think you’ve seen the darkest anti-hero that television can produce, you’re wrong.

“Dexter” blows your baddest bad boy (or bad girl) away. The drama is on the pay-cable network Showtime, where producers can get away with much more, but still, is America ready for a drama about a forensics expert who, in his free time, goes around killing people whom he decides are evil?

Showtime CEO Matthew C. Blank thinks so. “I just think that as you’ve had more outlets and more creative opportunities [on cable and network TV] that characters have evolved into something different than you’re used to seeing on television,” Blank said.

“We didn’t say, `We’re going to make it darker, we’re going to go further.’ We thought this character was intriguing was quirky was different enough that we could attract an audience with it. And we liked it, and it was a successful book,” he added.

The new shows on the broadcast networks this fall aren’t quite that dark, but we’re certainly seeing the influence of HBO, FX and other quality cable channels on their broadcast brethren.

On the glossy “Smith,” in which Ray Liotta’s character leads a gang of experienced thieves, more than one innocent civilian dies in the course of the robbery crew’s big heist. None of the thieves seems to have much remorse about it, nor does “Smith” executive producer John Wells apologize for the show’s edgy tone.

“People are expecting something from serious drama, from, for lack of a better term, high-end drama,” said Wells, a veteran of “The West Wing” and “ER,” at a TCA panel on the show.

“We no longer have worlds in which we do medical shows like `Dr. Kildare’ [or] `Marcus Welby,’ where the physicians are basically infallible. ... I think that we have to be competitive, constantly be aware of and competitive with what’s happening on basic cable, what’s happening on pay cable, what’s happening on broadcast television, and what’s happening in feature film.”

Speaking of doctors, CBS is also adapting the “House” model of a show about an extremely cranky guy for the new drama “Shark,” in which James Woods plays an attorney who, like Greg House, isn’t much concerned with making nice.

“This guy is an infant, morally,” Woods says. “This is a guy who’s never asked the question, What’s right and what’s wrong? It’s a whole new way of looking at things [for him], but he has old habits.”

3. Great pilot. Is it a show?

Usually the pilot for a network series has been so fussed over and focus-grouped that, even if it has potential, it can feel tame and stale. And many times a show with promise blossomed into something much better later in its run.

This fall, saints be praised, there is a bumper crop of extremely intriguing, well-executed pilots. But some of them look more like well-made films than TV shows that will be able to fill out a 22-episode season.

When you watched the first episode of “Lost,” you knew that was a show that had lots of stories to tell. But the relationship drama “Six Degrees,” in which viewers meet six New Yorkers whose paths coincidentally collide? Not so much, though I thought the pilot was exceedingly well acted and lovely to look at. And I’ll be happy to be proved wrong about the staying power of “Six Degrees.”

CBS’ “Smith” is another case in point. In that show, we meet a prickly, skilled robbery crew, but we’ve met such crews before, on “Heist,” “Thief” and “Hustle.” The pilot is shot as glossily as a feature film, and stars Liotta and Virginia Madsen are always formidable. But what if such high-profile talent and stellar production values aren’t wedded to characters and stories that will get audiences involved on a weekly basis?

With ABC’s “Ugly Betty,” which revolves around a sartorially challenged young woman joining a glossy fashion magazine’s staff, producers are aware that they don’t just want to do the heartwarming makeover episode, then be left with nothing left to say.

“She is going to go through a transformation, physically and, you know, internally. ... Of course she is going to have an evolution,” “Ugly Betty” executive producer Salma Hayek said at the TCA press tour. “What would be great, though, is that if we are very successful, we might get people to forget about it. We might get people not to notice whether there is a physical transformation or not, and they’re just really into the characters and what’s happening in there.”

4. Two trends in program names.

There areis not only a bumper crop of worthwhile pilots this fall - many of them have the same name. Well, that’s not entirely true, but one-word titles, a la “Bones” and “House,” are in vogue. The result is that this fall, audiences will be introduced to “Kidnapped,” “Vanished,” “Smith,” “Justice,” “Heroes,” “Runaway,” “Jericho,” “Standoff” and “Shark.”

How are we ever supposed to tell these shows apart? Their titles aren’t helping.

The subtrend is numbers-oriented names: “Studio 60 on the Sunset Strip,” “20 Good Years,” “30 Rock,” “The Nine” and “Six Degrees.”

It’s enough to make one want to watch “The Knights of Prosperity” and “Brothers and Sisters,” just because their titles are at least different. And they have more than one word.

5. The takeover of “thirtysomething” veterans.

Who would have thought that the cast of “thirtysomething” would take over television?

Peter Horton, who played Gary Shepherd on the groundbreaking ’80s drama, is an executive producer and director on the hit ABC show “Grey’s Anatomy,” and has directed scores of other TV programs as well. Ken Olin, a.k.a. Michael Steadman on “thirtysomething,” is an executive producer on “Brothers and Sisters,” and helped create “Alias,” among other projects.

Another “thirtysomething” veteran, Timothy Busfield, pops up occasionally on “Without a Trace,” a show on which he serves as an executive producer. He has also acted on and directed “The West Wing” and was an executive producer of “Ed.” This fall, he is directing, producing and acting on “Studio 60 on the Sunset Strip” (he plays a television director, just to make things confusing).

There’s a tussle, meanwhile, over the services of “thirtysomething” actress Patricia Wettig, who was a key player on “Prison Break” last year, but is attached to “Brothers and Sisters” this fall; she may end up appearing on both shows. Another “thirtysomething” veteran, Melanie Mayron, is busy acting and directing for television, and “thirtysomething’s” Hope Steadman, Mel Harris, is an in-demand actress who appeared last season on “House” and “Cold Case.”

What gives?

It’s all the result of the influence and mentoring of “thirtysomething” creators Edward Zwick and Marshall Herskovitz, Busfield says. “They created an environment for us as filmmakers,” Busfield notes, adding that the actors “all went to dailies, we could weigh in on character, they were open to everything.”

“We were all encouraged to [learn] whatever we could learn,” he says.

Apparently they learned well.