Capcom has said that the PC version of Street Fighter IV will use Games for Windows Live as the basis of its multiplayer system.
That also means that you will be able to use voice chat and unlock Achievements when the game comes out this summer.
Along with all that, PC SFIV obviously allows for higher resolutions than the mostly 720p-loving console twins.
However, Capcom has also included optional shaders based on the original artistic trailers - so there are watercolour, poster and sumi-e variations or the look established by the console versions.
You can get a sense of that in our Street Fighter IV PC screenshot gallery.