@Op i'd say go for the gtx 560 ti , or any other nvidia gpu , because it supports nvidia 3d vision

I just bought my gtx 560 ti with gs 600 psu , and i am very happy, i am just waiting for the asus vg278h 3d led monitor to be launched.
You will miss 3d if you buy radeon cards, 3d vision kit is not supported with radeon cards, you will have to contain yourself with
passive 3d which is rubbish. the aftermarket software's also don't make 3d a pleasant experience with radeon cards.
so, make your decision wisely, if you are not interested in 3d then you can definitely go for 7 series.
I'd like to get the record straight on the bold part and it hasn't got anything to do with nVidia and AMD.
Talking of 3D Televisions, if done right, Passive 3D is better than Active 3D. Passive 3D is flicker free and doesn't give you a headache. I have tried out Active 3D televisions too, and flicker plus headache have been my complaints.
Second, coming to Geforce vs Radeon for stereo 3D gaming.
You should read this page.
Two Compelling 3D Solutions With Strengths And Weaknesses : Nvidia 3D Vision Vs. AMD HD3D: 18 Games, Evaluated
Each has its strength and weaknesses. Overall, 3D Vision is slightly better. Not by a mile. It just edges it. But performance and quality indeed depends on the game.
GTX 560 Ti is not fit enough for proper 1080p 3D gaming. For 720p, it might be. For 1080p, you'd need a 2 GB GTX 560 Ti SLI.
imho, "3D gaming" is a gimmick. That's all. I'd comment on it after 2 years when it actually reaches a proper level. Avoid wasting money on it at the moment. Only an hour's fetish which gets outgrown quickly as far as games are concerned. Movies are fun though. But then each one as their own opinion.
Next, nVidia supports 3D in SLI. AMD is on their way in implementing it for Crossfire. A beta driver was released. Also, for AMD, you should be waiting for DisplayPort 1.2 3D monitors for 1080p as at the moment, HDMI 1.4a doesn't have proper bandwidth for 3D @ 1080p60.