Didn't Playtonic say they were going to incorporate ideas from both Banjo and Donkey Kong Country in their Rezzed presentation? I imagined something like Sonic Generations, but I hope that's not the case. Perhaps they meant some side-scrolling mini-games?
I wouldn't mind a few DKC-style mini-games... but the game should definitely be a clear-cut, traditional 3D platformer. Which I think it will be, or they've gone back on their promise not to give something completely unexpected.