I heard everyone will get 2 Ultras in this game. There will be new stages, music, bonus stages (that Ono was not able to add in before), and other perks. I think Ryu and Ken are redesigned too(Ken looks too comical in SFIV).

I think there will be releases of new characters and tibets in their blogs every week being released. Rumors is that Guy, Cody, Adon, Ibuki, Dudley, and other characters are being added along with the 3. But only time will tell.

Super Street Fighter IV Interview with Yoshinori Ono - PlayStation 3 Movies at GameSpot

Ono seems very passionate about this game, i hope for the best. Its also slated to not cost as much as a new game would, like it wont be $60.

YouTube - SSFIV interview FR

^ This is in another language, i dont know what it means,if anyone does that would be awesome. The only things i understood was that near the end it sounded like he was going for a revival in the Darkstalkers franchise, along with a push for Capcom vs SNK 3.