Just fired it up on my N800.
I've never had a palm device, so I'm not too sure, but it looked like it worked.
Anyone know where a good graffiti cheat sheet is?

Regarding portrait vs. landscape:
I saw a comment (on tabletblog maybe?), but I think he had it backwards.
When the "full-screen" box is checked, the display shows vertically in the middle of the N800 screen. Pixel-for-pixel correct, right-way-up, with no maemo borders, launch buttons, etc. (Oh, yeah, and wasting 3/5 of the N800 screen with a pretty background of your selection.)
When the "full-screen" is un-checked, the display shows up in a normal (not full-screen) maemo window. So when you hold the tablet with the d-pad & keys down, the Garnet window is right-way-up. Some of the left-over screen is now used for normal maemo stuff, as expected.
NO way, at present, of running the thing scaled (by 5/3) to just fill the N800 screen, or even scaled to just fill a maemo window. Nor of displaying 2 gvms side by side, which could be cool for testing multiplayer games.