I don't think it would be worth it for me personally, considering the sides are mostly peripheral for immersion feeling + the bezel gap size. I like the videos I've seen of the fw900 + side lcd eyefinity at 1680x1050. I'm hoping to do 1080 version.
You can see my FW900 next to those 1080P Samsung's and the 1080P vertically stretched image. If you correct for the aspect ratio of 16:9 with black bars the image will be quite a bit smaller, down to somewhere in the 20-21" view-able 1080P range.
I would love to find some 1920x1200 panels to match the same res across all three. Guess I can dream.
I've done quite a bit of research and 22-23" 1920x1200 LCD's with LED back lights just don't exist. Everything that is 120Hz are 1080P or 1680x1050 22" but CCFL thick and won't overlap the FW900 any good. The closest 16:10 I can find are the 60Hz 24" Samsung S24A850D, Dell U2412M and HP HP ZR2440w. They would be slightly larger than the FW900 image, which isn't necessarily a bad thing for peripheral vision but you would be limited with AMD cards as nVidia cannot do mixed refresh rates.
That would be one benefit of going 3x FW900 in Surround is that you could get 3-4 Kepler, run each FW900 off of one each card in the SLI setup. (I've always found nVidia to do Surround better than AMD Eyefinity).
I find 16:10 does Eyefinity/Surround much better than 16:9 displays. That extra height is really a bonus and you don't have as much of a crazy wide and narrow view as three 1080P screens lined up.
That about sums it up. No contest.
Yes, you can really see the IPS glow and back light bleed on the Apple versus the nice blacks on the FW900. And the motion picture is just LOL. Even 120Hz LCD's get smashed by the FW900 in that regard.