The Xbox 360 version of Super Street Fighter IV: Arcade Edition
received the Ver. 2012 patch on December 13th, 2011, but the PC version of the game was completely ignored. A month later, Capcom finally revealed that http://www.trueachievements.com/game.aspx?gameid=3970
would be receiving the patch and that it was expected to be released at the end of February.
Details on the exact contents of the PC patch were supposed to be revealed before the release of the patch. I'm afraid that the information was never released, but I can refer you to the full extensive list of notes for the console version of the patch. Follow these links for the official PDF file that can be found in five different languages:
In better news, the free patch has indeed hit the PC platform and is now available for download. For a quick preview of some of the gameplay tweaks in action, check out the trailer here