It has been done.
12.1-inch diagonal, SXGA+. First Toshiba used it in their tablets, later Fujitsu, Motion, Lenono. I read at least two reports over the years, of people customising their PowerBook G4 12-inch, installing this screen. Also ThinkPadders like such a screen, have put it in X31 and X60 (possibly also X40, I do not recall specifically).
A how-to guide is : PowerBook G4 Aluminum 12" 1-1.5 GHz LCD panel upgrade on iFixit
http://www.ifixit.com/Guide/PowerBook+G4+Aluminum+12-Inch+1-1.5+GHz+LCD+panel+upgrade/3117