They have finally built it: my dream laptop.
The key was a DVD/CDRW drive on an Intel-based machine with a 12"+ screen, more than 30 gigs of HD space, and capable of 512 megs of RAM... in a package weighing under 4 lbs. The Panasonic W2 blows it away--it's only 2.8 lbs, and has a sexy magnesium shell.
The only downside is that the display controller is integrated onto the motherboard, which means it shares system RAM, which degrades video performance. But for a portable development machine, this thing kicks ass.