An article/interview with Adrianne Palicki in Complex magazine’s Oct./Nov. 2004 issue seemed to imply that the Kara character - the "Supergirl" type girl played by Adrianne in the third season finale, "Covenant" - could be due for a return appearance soon.

The article says "the new season will reveal more of Kara’s personality." We don’t know if the article was mistaken or if Kara is indeed due for a return appearance; we have heard nothing.

Thanks to Unbreakable Lex for the tip.