If what the rumors say is true and each character will appear in the style they originally appeared in, then **** this game. I mean, I'm all for mascot fighters, but at least try to give them the same style.
That's why Super Smash Bros. works, that's why Jump Super Stars works, that's why even Punch Time Explosion works (hey, it's a pretty good game, although not nearly the same level of Super Smash Bros. or even Jump Super Stars). That's why Poker Night at the Inventory, even though I immensely enjoyed the game, didn't really work at all. When creating a crossover game, at least TRY to make each character appear in one uniform style. I mean, their overall appearance may look like the original, but at least the style must match.
Look at Viewtiful Joe in the versus games of Capcom, he has always been in the same style as the other characters. Just put Viewtiful Joe next to Zero or Captain America in Marvel vs. Capcom 3. Even though their anatomical style is very different, their artistic style are a match.
And, since we're on a Super Smash Bros. board, just take a look at Toon Link. Even he had his style ajusted to the rest of the cast. Even Snake and Sonic shared the same style. That's what makes a good crossover game work, or at least that's one part of it. You don't just smack down several characters together and call it a day. That's why a lot of MUGEN game creation teams take a very long time creating their games. They have to resprite every character that doesn't exist in the existing game style.
So yeah, if they're not using a uniform style for the game, I'm out.