Bumping this to say that after the initial doubts about Surround having tried more games and letting it settle in there is no way back after playing in Surround.
I couldn't play GW2 in Surround for the first couple of days due to Surround resolutions breaking the camera and playing on a single 1080p screen felt claustrophobic to me. Having the two peripheral screens black with nothing on and my measly single screen with the game on... I felt trapped almost

. It was very, very odd.
If you like eye candy you need to be prepared to sacrifice a lot of settings in some games to get playable FPS on a single card and even in 2 card SLI it is necessary sometimes to sacrifice any supersampling or other forms of high performance AA due to it requiring too much GPU power and framerates will be low. 2GB cards are fine for this resolution although I wouldn't try it on 2560*1440 x3 as it is fairly close on 3x1080.
An optimised set-up would consist of 3 GPU's (either highly clocked 7950/7970's or 4GB 670/680's) and you will be able to run maximum settings at nice FPS levels although this will of course sting the wallet somewhat (especially if you haven't already got an X79 motherboard!).
There are some serious driver annoyances to deal with which are irritating more than game breaking but nonetheless should be mentioned.
If you use your PC for applications such as Remote Desktop, Citrix etc then forget it. It doesn't work properly in Surround mode and you have to disable Surround to run extended desktop again. When you then want to go back to Surround the Bezel corrected resolutions aren't saved

. Additionally when switching between SLI and single GPU sometimes the cards (for me) don't wake up when disabled which is infuriating as you need to hard reset

.
Other than that though it's fantastic.