I think this game could have a ton of potential, but I just hope Nintendo doesn't go too over the edge with the side-scroller-ness. if it is what I think it'll be like, then it oughta be excellent. if they can make it as a big platform adventure, involving questing and backtracking like in other Paper Mario games, while still giving it that 2-D edge, then I'll be a happy man. a good story is a must. if they just throw it together with no plot/story whatsoever, focusing on the 'fun' too much, as they did with New Super Mario, then I might just be heartbroken.
incidentally, I just beat Thousand Year Door the other night, and for the first time in my life, I can safely say I have a favorite game. seriously, this game is driving me insane, I actually feel really bad that I beat it.