His contract with the show will be up and though the young actor hasn't exactly got a viable film career to jump into (besides the forgettable remake of "The Fog" that he did, the only other thing he seems to have going on on the big screen are those incessant "Cheaper with the Dozen" films, where he plays kid number 2) he's understandably going to be a little tired of playing a teenage Clark Kent and itching to play anything but for a while - even if that is Steve Martin's tweenage son in another umpteenth "Dozen" sequels.
Welling hasn't indicated one way or the other yet, but the fact that he's no longer legally obligated to file stories for The Daily Planet does suggest he might look for work elsewhere next year.
"Smallville" executive producer Darren Swimmer also tells TV Guide this week that he's prepared for a series finale if it comes to pass, but there are still a few things he wants to see Clark explore before everything is wrapped up. "Clark's now in full control of his powers and basically accepting the fact that he's going to become Superman," Swimmer said. "The formation of the dual identity is what he's going to be negotiating from here on out. He'll start to experiment."
If The CW does chop "Smallville", Swimmer also has a suggestion for them : Give "Martian Manhunter" (played by Phil Morris on the series) his own hourly adventure series. - SOURCE
Here I hope this opens the door for Tom to get the chance at playing the big screen SUPERMAN some time soon... I would love for the show to continue for another 2 seasons at least! But Id much rather see Tom on the big screen as SUPERMAN!