That would be pretty sweet! I'm a big fan of the desktop replacement market anyway (as long as it has adequate cooling - which has long been the problem with putting decent GPU's in DR models), and Quad-Core laptop...that's FilmGirl's dream.
Remember though, the big problem with Pentium 4 Desktop chips that they had running in a lot of the high end desktops a few years ago (before Centrino and the smaller micron chips became more standard/efficient) was a) they ran hot as hell..like HOT and b) battery life was terrible (which is sort of moot for desktop replacement, but if you can only get an hour if you do need to take it somewhere, what's the point of even having it as a laptop -- I'd rather build use a Micro ATX case and high end LCD and c) overheating was a huge problem.
Still, very, very cool.