To the OP: As others have made clear, resolution doesn't go up linearly with screen size for TVs. They currently max at 1920x1080 (HDTV, Blu-ray etc) or 1920x1200 if it is marketed as a monitor. However, PC monitors go far above this in resolution.

I run the DELL 3007 (30" with 2560x1600). I use the standard maximizer layout from keyclone for this screen size which makes the text on the alts somewhat tricky to read but usually there isn't anything I really need to read there that isn't on my main. If there is something i MUST look at on one of the alts, I use the PiP feature of Keyclone. Sometimes I wonder if the alt screens couldn't just be minimized to the task bar and PiP'd up as needed.

Personally, I like the idea of just having a single PC and single screen so my workspace is not cluttered, but that's just me. I'm also pretty anal about my cables and whatnot. Although I can appreciate the advantage of a multi-monitor setup, I don't want all that shit on my desk. I also have all my cabling dressed and routed through piping attached to the back of the desk.

I've played WoW on a 1600x1200 50" LCD via a DVI cable and it was definitely playable for a single toon. The problem is, you definitely can't sit 18-24" from the screen because of the pixel size. It was cool to bring a second PiP screen with NFL on during a session of WoW! As long as you're not watching the alts much, though, you could definitely multi-box from the couch.