If the show were to graduate, as it were, to being a fully-fledged Superman show with the same cast, sure, but then it wouldn't be Smallville anymore. The show, as is, has long run its course. That isn't to say that it's just been downhill since (insert earlier season number). In fact, despite ups and downs (for the latter, I'm looking at you, season 7), it's had an overall rather enjoyable recent couple of seasons. I do think that, ideally, the show shouldn't have run longer than 5-6 seasons (imagine cutting the fat and condensing the best of show down to a shorter run), but whatever. We've had ten fun years, and, though I'm sad I won't have a weekly Superman show to look forward to, I'm excited as all hell for the finale and to see the last decade of journey come to fruition.