Hmm... the glowingly positive impressions from this thread are making me excited for this game... but on the other hand I'm pretty hesitant about what I saw in trailers/previews, etc and then I saw the reviews, which haven't helped.
I understand them wanting to stay fresh, and not become stale as a series, but TTYD kept it fresh to a degree, just in a different way: Level design. E.g, the Glitz Pit chapter; a constant stream of battles getting harder and harder, while working on a mystery. Also, Excess Express chapter; Pretty much NO battles (besides that small dungeon midway through), lots of talking to people, finding information, etc. Of course, that's only 2 chapters, but they were by far my favourite chapters in the game. Why not keep things fresh by bringing in new, interesting concepts in level design, like those 2 chapters?
I don't quite understand why IntSystems feel they need to completely shake up the gameplay mechanics with new entries. I suppose being on a handheld makes certain changes necessary.
Eh, I'll be buying it Day 1 no matter what, since it's a Paper Mario game (have to wait until December unfortunately). Hopefully I end up liking it more than Super Paper Mario.