I won't mind if Gief or Sim are back in. I'm sure they'll make a lot of people happy.
I just hope they have some cool design changes that really play to their personality and strengths, like Ken's. Even subtle stuff like Bison's coat/white hair would be good.
For example, Gief could wear the red cape that he's had in some intros in the past.
Would be a nightmare to fix the clashes/clipping, but I think that would give him some new visual flair.
At any rate, I just hope Urien is in. I never really gave him much of a chance in 3S, but I can see him being a perfect fit for SF5.
I remember being so excited when Makoto and Dudley were announced for SF4, as they were my mains in 3S. This time, I have no real "need" for any character, and I'm in a peaceful place when it comes to the roster, but for some reason, seeing Urien again would really make my day.