As predicted here is the offical introduction of the Street Fighter III characters coming to Super Street Fighter IV! Ibuki the female ninja, Dudley the gentlemen's boxer, and Makoto the Karate girl. I played Ibuki little bit in Third Strike and I'm looking forward to using her in SSFIV! And seeing Dudley pummel Balrog was just epic and Makoto...well she's aight but I'd rather of had Alex, Yun or Oro in her place.
There's only one fighter left to reveal, Hakan. Rumors say he's middle Eastern and is fighting for oil, if you watch the trailer through it's entirety there's a hint of him at the very end.