Looks like its split between the 2 giants. One thing I will say is that Microsoft have made some changes and you no longer need to stay connected to the Internet and you can chafe games.
What I am pissed off about is the lack of backwards comparability.
Personally I am leaning towards the Xbox only because as a fighting game player I want to play the new killer instinct game. The best games will be released on both platforms anyway. My advice is if you play online with mates, just make sure you get the Same as them.
Oh and for the Sony guys, you now have to pay to play online