TvC’s arcade board is based on Wii hardware. Porting the game and system over was probably very easy for Capcom. Also TvC outputs at most 480p from what I remember. So putting TvC on the Wii (a 480P system) as opposed to the PS3 and 360 (720-1080p) makes a lot more sense. It was designed to be ported to the Wii from day one most likely.
SFIV is a 1080p game and makes far more sense to port it to new generation consoles that are HD capable (and of course PCs). Considering that SFIV has had pretty excellent sales I don’t see the motivation for Capcom to port it to the Wii, PS2, or even the PSP. SFIV on the Wii would be horrible looking compare to the PS3/360 versions.
Also who wants a game watered down across so many consoles anyways? Look how bad T6BR’s port turned out when Namco split the development team into PS3 and 360 teams when they were originally tasked with just optimizing the game for a PS3 release.
Less is more in this case. SFIV was a good port. Arcade perfect from what I understand, no downgrade in graphics, and dual platform launch (PS3,360).