Just crossposting to give people here information:
2xGTX 470 on water, 800 core, 1950 memory.
I could only tinker for a half-hour before bailing for work so I only had the time to try BC2, World at War, and Serious Sam HD. Everything seemed to work, though I had the wrong version of Widescreenfixer so World at War was stretched out like mad.
I averaged 45-60 FPS (Vsync and triple buffering on) in BC2 single player on the jungle map when it came to the actual shooting and fighting and smoke, but in the part preceding that, where you maneuver a boat through some rapids, the FPS tanked into the teens. Probably something to do with all the effects of water sloshing around. This was using 5760x1200 at 4xMSAA, everything max.
Serious Sam was unplayable at 8xAA, everything max, but I don't know what kind of 8xAA mode it tried to enable since that option doesn't even exist anymore in Nvidia drivers. Going to 4xAA smoothed things out considerably and I got 50 to 60 FPS.
I'm glad Nvidia has finally gotten this thing out the door. I went with Nvidia because there was no way I was going to play on three monitors with only one GPU, so the SLI requirement was a bonus, not a problem, for me, since it meant that Nvidia had to get multi-GPU Surround right, whereas ATI's implementation seems hit or miss. The SLI scaling hopefully proves itself superior to CF even moreso than in regular gaming, especially with the extra video RAM. And finally, yes, no Display Port.
Can't wait to go home and give it a more thorough run. Great to have coincided with the Steam sale!