I don't even want to play until the patch comes out. One thing I haven't seen mentioned is the change in hit recovery in pvp, though i guess that can go along with arena changes. Theres also new things in the options, one of which is a V-sync option which can make the game run MUCH better if you're on a high end system. I've always had weird delay/frame rate issues which is freakin terrible as a fighter, but once I changed that option OMG everything worked so much better.
AND OMG, pvp evasion tweaked!!! I lose SOO many matches strictly because of evasion. When you miss someone in the middle of a combo and they can just counter combo you for 50% health, it's kindof lame.