Not every character fireballs in SF. Fireballs can also be a weakness. Tekken on the other hand can juggle. It's be interesting to see how they streamline the gameplay. I'd imagine it'd be play like SF4 with tag team action. Just imagine a match up like Ryu & Kazuya vs Sagat & Bruce...
Oh right :P but it does pose some interesting questions... and *apparently* there's going to be 2 versions, one made by Capcom and the other one made by Namco. Perhaps the Namco one is going to be more Tekken like? more technical etc.?
Apparently there's already a 2D fighter named Capcom x Namco on PS2!
Nah, there's a RPG called Namco x Capcom (only released in Japan). You might be thinking of SNK vs Capcom: SVC Chaos. Other than that, there's just Marvel vs Capcom 2 and Capcom vs SNK 2 on PS2.