Capcom knows exactly what to look for, and I'm pretty sure they won't let this game be as much of a complete fuckup.
I don't know if they (capcom) openly embrace balance in their fighters. Which is fine. But with a roster as large as MvC2/3, with as many supers/assists and general shenanigans, there will always be something overlooked or some major glitch. It is impossible to game-test this. This is why namco releases tekken into the arcade, gets feedback from korea/japan, and edit/fix mistakes, repackage, add a few new characters and put some letters on the title like D or B or R. Many scoff at this tactic but you tend to love namco if you are actually in an arcade enjoying bob's toned down ws2 or julia's lack of B! out of d/f 1 +3_4 being corrected. That being said, capcom will throw this game out to the masses, there will be horrible broken elements like gambit being able to snap back an opponent and jump off the screen for ever and ever, amen, or atomic busting somebody into the floor to be stuck permanently, and some korean fight team will figure out how to break a character past God tier.
In addition, mags and storm were good because of their 8 direction air dash mixup into infinite followups, which is actually really hard to do on a stick and impossible on a game pad. I know many complain about it, but i was never able to get the hang of it so i give props to those that can. Sentinel on the other hand, had the highest starting defense in the game, every move did CHIP damage (stupid) and he had the fastest air dash/air cancel in the game (with two plausible assists). AVHB was not the only thing that made cable dumb. But if you look at the entire god tier from MvC 2, it was all marvel. Two of the three best assists were also marvel. My guess is, Capcom will try to up their side in MvC 3 because of their roster non-factor in tournament play from the last game.
in the end though, this is a really FUN fanboy/girl game that should be enjoyed casually. I can't wait to play this in the arcades and I really hope hsien-ko wasn't anakaris' replacement (though, it probably was). Anak was the the hizzzzieeeeee and hella fun to play!