I'm sorry but I fail to see where you can see two different resolutions at the same time: the background screen is clearly displayed in the higher frontscreen's resolution (that's why Quake appears in a small part of the screen).
Now, what I'd like to see is quake 1 & quake 2 running, at the same time, on two different screens (using, of course, a single graphics card with dual-head). Now, that would be nice, and useful.
