Yes, on the question whether or not it'll be the biggest fighting game this generation. Probably even just the WiiU version separate.
I think the WiiU version will easily come out on top, simply because the console experience will beat the handheld experience. That said, the 3DS version should do very well, because it's the first handheld entry in an extremely popular franchise and looks amazing. I don't see the WiiU version beating the Wii version, because of the WiiU's lower install-base and the fact that the each version will slightly cannibalize the other.
I'd say;
WiiU: 7.5m
3DS: 4.5m
for a 12m total.







