The excellent http://www.kryptonsite.com
reports a Teen Titan will be heading for Smallville: "The fifteenth episode of Smallville's fifth season will feature a guest appearance by a popular member of DC Comics' Teen Titans. The hero in question this time around is Cyborg, a character who rose to popularity in the classic Marv Wolfman/George Perez New Teen Titans comics who also is features on the Cartoon Network's Teen Titans animated series. The title of the episode is, of course, "Cyborg.""
More details from titanstower.com as they develop!