You really do need a four-megapixel display like the Dell 3007WFP in order to take full advantage of GeForce 8800 SLI with today's games. Even then, a single GeForce 8800 GTX is often fast enough to drive a 2560x1600 monitor quite well without the aid of a second GPUwitness our test results in Quake 4, Half-Life 2: Episode One, and even Oblivion. Heck, even the G80's CSAA 8X and 16X modes have so little performance penalty, one doesn't really need SLI for them. The big exception is Rainbow Six: Vegas, which is brutal at 2560x1600 on everything but a pair of 8800 GTXs. As the first Unreal Engine 3 game we've tested, it may be an indicator of things to come, but I'm not quite sure. It may also just be a lousy port from the Xbox 360. That said, more intensive games are always coming, and there will likely be a reason to upgrade to a second GeForce 8800even a second GTXat some point in the next year or so. For now, though, you may want to keep a PCIe slot open and wait.
That said, I've played through decent chunks of both Rainbow Six: Vegas and Oblivion with a pair of 8800 GTXs in SLI on the Dell 3007WFP, and it's a glorious thing, having smooth-as-glass frame rates with incredible image quality on a massive, detailed display. If you have to means to treat yourself to such a setup, the visceral experience certainly won't disappoint.
I wish I could say the same for the driver support, but Nvidia doesn't yet have all of the wrinkles ironed out of GeForce 8800 SLI in concert with wide-aspect displays. I do expect most of the problems I've noted to be fixed eventually, but with Vista imminent, I fear those fixes may be on the backburner for longer than usual. We'll have to see. When they come, they may be accompanied by all kinds of other new goodies for 8800 SLI, including things like CSAA 32X antialiasing and three- or four-GPU SLI daisy chaining. At that point, we'll have to hope new games are out to harness that power properly. An eight-megapixel display would be well and good, but at this point, I'd definitely rather have better pixels than more of them.