As far as I know, the news on it says that it'll play like a 2D game.
Were you really expecting 2D graphics, however? No doubt, I would've preferred 2D as well, but it's just such an unrealistic expectation considering, well, many factors (the lack of 2D talent in the mainstream industry at this point, the 3D trailer, the ease of making and using 3D over 2D, etc...). I think it looks fine how it is. My main gripe is with the rather bland background characters, and a bit of odd anatomy on Ryu (huge feet, and the chest is funky, though I'd say huge feet have always been a stylistic staple of SF games). The colors and rendering look nice, and I'm glad they're not striving for a super realistic look with this that the other 3D fighters do.
KOF XII has been promised to be the best 2D game ever, so I guess you can still look forward to that.