Ok, I'm going to get into this now...
360 is going to be on top. Why? PS3 keeps pushing it's dates back, plus all the 360 blockbuster hits are going to be released this thanksgiving and christmas holiday. About the time PS3 releases, it better release some blockbuster hits when it's released or it will fall hard.
The price, is another hit. I would think Microsoft will either lower the price of the 360 or come out with a special edition during the PS3 release. Microsoft has the edge, because they started the market early, they knew there would be some problems by rushing the release of the 360, but would have them ironed out in time.
Alot of developers are going to the 360 and now there are more and more Xbox only releases. Metal Gear Solid and KillZone is the only thing going for Sony right now. I just wish Metroid would go to Microsoft platform!