Don't know if anyone is still interested in this project, but I sure am.

So far I have a very usable Jaunty installed on my N810. I have the following working:
LXDE Desktop
Touchscreen
Right click support by holding the stylus down
Wireless
FN key
Pipe mapped to fn+z, tab mapped to fn+space
Numbers all work
Automatic login

I am still trying to get sound working, but I think I am really close.
I'm also trying to get a battery indicator, which is proving quite difficult so far.

I have not even tried the camera, microphone, gps, or bluetooth yet. I want to install Skype, but it isn't available in the Jaunty repos...

So in short, yes the GUI is working.