I think the most interesting thing about UMvC3 (besides Wright) is the question of whether zoning will really be strong in the long run like people seem to think. Zoning is like, barely feasible in Vanilla, and by feasible I mean feasible, not tourney-winning (unless you count Phoenix I guess).
So we have Dormammu, who's apparently getting a series of buffs to his zoning game, some of them quite major. Trish is apparently getting buffed a lot, I think MODOK is getting buffs (despite being kind of underexplored in Vanilla), Chris is buffed, and I'm sure there are others as well (like Arthur or something. Haven't really paid much attention). The X-Factor nerf arguably benefits zoners, and much of the old top tier (which was largely rushdown) is being nerfed too. And then you have characters like Rocket Raccoon, Dr. Strange, and possibly Phoenix Wright having seemingly strong zoning games.
Capcom has clearly put a ton of effort into making zoning actually feasible this time. But it's still like they're taking a big pile of cool-sounding ideas and shoving them into a game that seems to inherently favor rushdown. It'll be really interesting to see what happens.