I can't say it was a roaring success, but it's certainly no disaster. On first boot it worked! A quick flash of the screen and all seemed well, except for a message saying:
Code: Select all
gma500 0000:00:02.0: Invalid ROM contents

I'm in no hurry to play around any further (this was a very quick fishing trip), but if anyone wants the kernel .debs I made they're here. I can't promise my kernel config is any good - I started with BuZz's config and then guessed a lot.

Oh, and I always compile with thermal.psv=80, so if you're not happy about that, don't use the .debs.
EDIT: 22nd May 2012: Removed the link. It was buggy as hell.