Legit Reviews posted an article on AMD Eyefinity. Here's a taster:

MD obviously spent a lot of time on the Eyefinity drivers and they seem to be fairly solid even though the graphics cards won't be launched for a number of weeks. AMD had a system up and playing the upcoming DX11 racing game, Dirt 2, at 7680 x 3200 with solid performance from the looks of it. Playing games at this resolution will tax the system, but obviously the new Evergreen DirectX 11 graphics card has the muscle to run the game just fine. We got our hands dirty this morning and tried out gaming across three 30" displays in a 3 x 1 configuration and we must say it's very different as there is just so much screen to look at. It's a game changer for sure, as the gaming experience is a lot different.