It depends on two factors:
1. price cuts. There will be a $50 redcution in 2011, that's for sure. No way Sony is going 2012 with $299 PS3. Now the question is, do they reduce the price before 2011 or not? I doubt it, but I can see them doing "inoffical" pricecuts with bundles and more included hardware, for example $299 PS3 with Move and navigation Controller, or two Moves (though unlikely).
2. Kinect. The big question mark. The sales of Kinect by the end of 2011 will be an indicator of the success. If it sells 2.5-3 million or even more, I consider it success. If it's less than 2,5 million, I don't think it will lift off.
And here's my prediction: If the PS3 hits $249 or if we see bundles with Moves still going for $299,and if Kinect sells less than 2.5 million units, PS3 will dominate 2011. If only one of the conditions is fulfilled, it will be a tie of PS3 vs. 360. (or with the Wii, for that matter). If Kinect is a success and we still don't see a pricecut of the PS3, it stands no chance in 2011.
updated: 14.01.2012
playing right now: Xenoblade Chronicles
Hype-o-meter, from least to most hyped: the Last Story, Twisted Metal, Mass Effect 3, Final Fantasy XIII-2, Final Fantasy Versus XIII, Playstation ViTA
bet with Mordred11 that Rage will look better on Xbox 360.