i worry about the quality for thus sized images.
my current gpu (4870) is O.K. at 2560x1600 and reviews say the new 5870 is like 2x as fast... but thats not enought for resolutions of 5120x3200 (4 displays of 2560x1600) as this is 4x more pixels and you have only twice the speed --> it may be 50% loss of FPS? (math isnt my favourite

)
anyway the border of displays near the middle of FOV sucks! better get a 52" display and sit 1m in front of it

(without goggles, then i get 8xAA for free, it looks amazing *lol*)