My housemate and I went to Wal-Mart at midnight to pick up MvC3 for 360. We played about two hours and just quit.
First off, after ten years it's nice to play a sequel to Marvel vs Capcom 2.
Second, this game is weird. Weird in that they redid just about everything. It's not necessarily bad, but different. For instance, I was on media blackout aside from character reveals so I had no CLUE that they replaced the classic low punch, low kick, medium punch, medium kick;etc button layout for three attack buttons and a launcher button. At first sight, it feels like simplistic, but after playing tons of matches it adds a lot of depth to the game and characters have a ridiculous amount of moves in comparison to MvC2. It took us about an hour and a half to get used to the feel of the game, something we weren't expecting.
Even characters we were expecting to play a certain way, after playing a lot of Capcomfighting games, played differently than expected. Ryu has a floaty jump, for instance. A lot of characters have floaty jumps and it took me a while to find someone I was comfortable with.
One thing I don't like is the new partner assist buttons. I hate it. I like how in past games you just press two buttons together to tag out, but here you have to hold the partner button to tag out. It feels unintuitive and slow in comparison.
In terms of overall fun factor, so far, I'm having a blast with Zero, Deadpool, Amaterasu, X-23, Magneto, Storm, and some others.
Overall I'm really loving the game and I'll purchase my own copy tomorrow when I go pick up Tactics Ogre and Dragon Quest VI. It doesn't really have the charm and personality of past games, but the complexity and learning curve is really off the charts for me, and it's going to be a lot of fun learning Marvel vs Capcom all over again, because it feels completely different to me.