I'm in the same boat, actually. I actually like the roster, and I think it's the Warzard characters and Karin that's leaning me into getting it. Now Capcom only has to use Karin 1 more time to match the amount of appearances she's made in SNK-made games. (Oh how Capcom gave some of its characters, the shaft)
Actually, CvS chaos is one game in which front-step and certain included characters saved it for me(it may have its faults, but Tessa was a work of near genious, and there's some real fun characters with exhaustive move sets). It sounds like a similar case, with this game. The notion of teaming up Karin and Yun and seeing how they can go against people like Jedah seems too enticing. Still, I would've liked to see even more unusual characters make the roster. I would've been interested in seeing Makoto make it in instead of Chun Li. Chun Li never really felt like a real SF3 character, to me. Just an add in.
Though it does feel that this game is similar to Capcom as was SvC chaos was to SNK. A game that almost lives off of its fun character selection and doing their best to include some ODD and unusual characters, from their roster. Sadly enough, that's exactly what will keep me buying the things. I just get pumped at seeing the less-used flock make comebacks in a strong way. I'm still optimistic that Capcom's Lilith will make a return just like Cham Cham. Though Cham Cham deserves a comeback given she's the most fan favorite fighting game character in existance, to consistantly get the shaft when it comes to game appearances. Even the constant running jokes (they seem to show up in backgrounds but never come back to fight) Mr. Todo and Eiji got more representation.