Our buddies at MOSR have gotten in on this:
From the article:
The larger 1920x1200 Powerbook prototypes we've seen were made with cooling high-end G5 processors in mind: somewhat thicker than today's PBG4s and with displays of 19, 20, or 21 inches to allow for sprawling heat-pipe and liquid-cooled structures as well as a huge ATi Radeon 9800 Mobility graphics card.
Okay, first, let's just clear something up before we proceed: THEY haven't "seen" shit.
But, just for the sake of this post, let's pretend they did. A 21" PowerBook?!?!
Well, the cool thing is that they could probably get it to about 3/8" thick, at that "sprawling" size...