Here's the Q&A on the subject presented at TVGuide.com:
Q Is Clark Kent finally going to become Superman this season? —Lauren, Palm Beach, Fla.
A Sounds like we’re close! Smallville exec producer Brian Peterson tells me that the black blur suit Clark has been wearing this season was designed to be only a temporary bridge to the long-overdue Superman unveiling they are now plotting. “Given the Clark Kent everyone knows from our show, it would come out of nowhere to have him automatically start wearing the [Superman] suit,” Peterson says.
But once Clark comes to embrace his human side this season (with a little guidance from costumed Justice Society guest heroes Hawkman, Dr. Fate and Stargirl in a January episode), Peterson says Clark can start wearing his classic red-and-blue. The season may even conclude with Clark building a new costume with a bit more color, much as Tobey Maguire’s Peter Parker did in the first “Spider-Man.”