Alright, so it's no Ultra Street Fighter IV, but Capcom is working on an upcoming mobile Street Fighter title in tandem with Nexon. Sounds a bit strange, I suppose, but since it's a mobile game it makes sense.
Street Fighter IV Arena is releasing in Korea, but there are few details surrounding the title as of yet. Of course, as Siliconera points out, if you're Korean and have an eligible Korean phone number, you can apply for the closed beta and laugh at all of us poor saps who can't join in yet. Hope it's awesome.
Capcom And Nexon Team Up For Street Fighter IV Arena [Siliconera]