They're hyping some new "Promo engine", which should help with rivalries and create branching storylines hopefully. I'd also love to see:
1) Permanent manager assignments
2) Many, many more rivalry slots
3) More variety in the rivalries (run ins, promos, etc., rather than the same 2 guys wrestling each other every week)
We'll see, seems like they've made major improvements in lots of areas already. Hopefully, as someone mentioned above, they'll let us play entrance themes from USBs somehow.