Idea.

What would you think about having an ASUI feature that toggles off and on the status bar on the desktop?

I've mentioned this before.
http://talk.maemo.org/showthread.php?t=52562

If there was a way to save the status bar settings file, and then completely remove it from the desktop, you could also restore those settings and bring the status bar back.

Would this then give us a full 800x480 desktop on all applications?

To be honest, I really don't use the status bar 99% of the time when I'm on my tablet.

I think you need to do a killall hildon-desktop for the changes to take place though which takes like 15 seconds.