Perhaps showing preference to the 2D art style of Street Fighter III, one loyal fan has converted the new fighters of Street Fighter IV into sprites that blend perfectly with the older game.
As seen in the example at right -- and the handful of other equally striking pieces at this Shoryuken.com forum post -- artist "steamboy33" has taken the dimensions, stance and aesthetic style of each of Street Fighter IV's new fighters and matched them almost flawlessly to the hand drawn style of its predecessor with care enough that they seem to have originated there.
Sadly his work is limited to these static images and sprite rips. To hear him and other sprite art fans on the thread tell it the effort to simply craft these static sprites is immense. Actually creating fully animated sprites for each character would take years of dedicated work.
Even so, it's a damn impressive bit of creative work and almost makes me want to pull Street Fighter Anniversary Edition down from my shelf and remind myself exactly how terrible I am at that flavor of Capcom's seminal fighter.