Hell yeah. Multi-size overlapping windows have been around since at least 1981 (running on only 384 kB RAM too!).

A proper desktop UI is quite usable even on a 7", 800x480 display (I've tried). Easy Debian on Maemo shows that it is just about usable even on a 3.5" displays of the same resolution. There is really no reason for tablets to push the one-app-full-screen nonsense. Not even on 7.85", 2048x1536 screens.