On what settings can I run BF3 with dual 6950's?

[apav]

I'm making a desktop with an i5 2500k, 8 gigs of ram and 2 dual 6950 cards or a gtx 580. I'm assuming these dual cards perform better than a GTX 580, for a little extra $.

I'm aware the specs haven't eben released but based on the hardware the played the demos what would your guess be? Which will run better and will the 6950's be able to handle BF3 at ultra at 1080p smoothly?

I'm also looking at the nvidia version how does GTX 560(what is ti?) sli compare to 6950 crossfire?

Also, by christmas will the next line of gpus be out? I might wait for them if they perform better.

 

[apav]

If the new gpu's are coming out within this year, I might consider getting the AMD bulldozer as well.

Can you overclock dual cards? And how much of a performance booster would that be compared to say the 580?

Thanks for the insight