But would Nintendo be willing to partner up on a game that they know would be going to non-Nintendo Console?
I mean, Nintendo has done it before. But those were the rare exception, with a specific condition (like the game being educational)l.
Only the Nintendo Wii Version would have Nintendo Characters, but If you want better graphics, the 3DS would be a better choice, though it would have less Characters than the Wii Version, and the Wii Version could hold over 110 fully funtional fighting character models on a dual layer disk, (not including alt. colors) while keeping great fighting Gameplay on both Wii Remote/Nunchuk, and Classic/Gamecube Controllers, while allowing 3DS versions to connect to allow more characters on the system with a better graphics engine, the 3DS version could also run save records exclusive to each system, rather than have game card save files.
The X-Box/PS3 versions would add more Sega, Marvel, & Capcom Characters, while allowing custom fighters, & X-Box would have one of those Halo soldiers that actually has a name, as an exclusive character, While Playstation 3 has iconic game Characters like Lara Croft (Tomb Raider) & Solid Snake, and other Playstation Fill-ins
007 (James Bond) would be a good character for a Wii/3DS exclusive though!