At first glance, Street Fighter IV on the iPhone - coming this March - looks absolutely gorgeous. But it's most likely what you don't see that's really the problem.
While Capcom built the iPhone's SFIV from original SFIV assets to create one of the most beautiful iPhone games yet, the virtual controls look like to be layered right on top of the two fighters, making all the character artistry in the world a moot point*. I'm one for authenticity where it works, but maybe reconfiguring the layout so that health bars took up the bottom of the screen would have been a safer call.
It should be mentioned, however, that the Bluetooth-enabled head-to-heads sound fantastic.