Well, what do you think/hope the innovations will be? Which things do you hope that will be back (or not)?
For my part:
1) Gore: I was disappointed by the lack of it in the 5th one. There's no doubt it'll be classified as Mature/ PEGI18+, so there's no excuse why it should be assent. I mean, there's a reason why Don Salvador is well remembered and nobody recalls/cares about the guy with the chainsaw in RE5.
2) More enemy variety: especially the bosses. In RE5 there were only the giant, Wesker and ... that black slimy thing aka Ouroboros (worst RE's virus EVER). Also, a variety of enemies with different abilities/weak point would somewhat compensate the (most likely) lack of puzzles.