I'm sure the demos are really cool. And as someone who plays GranTurismo 5 on my PS3 (for a whopping two hours every three months), I _love_ the idea of wrap-around. BUT From a basic standpoint of graphic information, we're talking about:
- the resolution of the display area, which impacts how "jaggy" your vector-lines are, and
- the resolution of the textures, which, when put in the context in the 3-D environment, may have greater pixel density or lesser pixel density than the number of screen pixels it has to render itself into.
Multiple screens (and thus very high pixel counts) give you less jaggy lines, but I'm not sure how critical that is when rendering at 1080p or better anyways. If the textures are the same resolution as before - i.e. appear kind-of smeared-out and manufactured when the 3-D rendering puts the object close to you - then the more cost effective solution is to go with one high-res monitor that spreads the display over a large area. (For example, a projector or a big-screen HDTV. I use the latter on my PS3 for GranTurismo 5.)
However, once the game publishers crack the whip on their artists, and come out with games needing Blu-Ray or even multiple Blu-Ray to distribute the graphics textures, then Katy, bar the door! THEN we start to enter a new phase of gaming, and head deep into Virtual Reality.