Except we're far away from that, now. Shouldn't we take a step back and judge a game based solely on its merits instead of comparing it to our expectations from more than half a decade ago?
Super Mario World is one of my all-time favorite games (it's in my top ten of all time) and even I have to admit that NSMBU is, from a gameplay and polish perspective, almost as good. It will NEVER have the nostalgia or aura of mystery around it like SMW, and the soundtrack is sort of bland by comparison but from the standpoint of design and world building and gameplay? It's on par with the best.
The difference is that Super Mario World was made for one player. NSMBU was made for multiplayer and I really got the feeling that this is not for me who wants a single player game.