As someone who actually owns Street Fighter IV on PC, this makes me a little sad: it doesn't look like Super Street Fighter IV will be gracing the platform.
Seems that while the original game sold quite well, it was also "number one in piracy". While this left producer Yoshinori Ono happy that so many people were enjoying his work, it also left him with the impression that, to maintain a sense of worth about the Street Fighter brand, they couldn't in the future be giving the game away for free.
Meaning a PC release seems unlikely, especially given the fact Ono says Capcom wouldn't release the game as a Steam-only download, since that'd be unfair to PC owners without Steam.
Did nobody at Capcom tell him pretty much everyone has Steam?
Don't rule out all hope, though, PC gamers; he concludes saying that should an adequate copy-protection method be found, the arcade version is practically already running on PC code, so a port would be a piece of cake.