I guess I'm the first person to post an NVidia surround system on here, so I might as well share my experiences with it. I bought my 2 GTX 470's about 4 months ago to update my aging Q9450/HD4850CF system; I was considering 5850 CF, but the need for a $80 DP to Dual link DVI adapter turned me off (single link ones weren't available back then). I got my three 25.5" Asus VW266H monitors on the cheap ($60 MIR's for each!)
The biggest problem I had was that I have a small house and a small desk. I just couldn't fit three monitors on the stands on my current desk and I didn't have the space to fit a bigger desk that I could fit three monitors on. I solived this by buying $20 clamp mount brackets off Monoprice.com and modified them by drilling holes so that I could bolt them to the sides of the desk. To cover up the gaps between the monitors taped black electrical tape over the caps. It actually blends in very well with the bezels.
I actually really like the way my case turned out considering that I didn't do any drilling/modifications. I was able to exhange my DFI LP UT X48-T3RS motherboard (CF support but no SLI) for a XFX 790i Ultra (SLI support but no CF) in an even trade through a great deal I arranged with someone else online. Better than that, my new MB was able to get an additional 266MHz out of the CPU.
I'm still frustrated that changing from surround mode to individual display mode requires you to click through 6 prompts, but I can't be the only one with this problem so I have hope that NVidia will implement hotkeys in the future.