These days they milk shows for all they're worth. It's rare that a show can keep going for so long without being canceled, so they'll just keep making 'em until people get sick of it, they run out of story ideas, ratings drop, and the network cancels it. Seriously, when *is* Smallville going to end?! I stopped watching it after the second season or so, I could've sworn it would've ended by now. It started out really nicely and it got weirder and weirder as it went, but I guess people still dig it!