Ubuntu Jaunty is definitely the way to go; I tried installling Ubuntu MID in my chroot, it installed completely but boy, I'm warning you, don't run it in a chroot on display :1 using Xephyr (unless you know something I don't)... it conflicts badly with maemo (they use the same services) and it ends up crashing the tablet.

LXDE in Ubuntu Jaunty, on the other hand, is nice, especially if you install the Human theme and the Ubuntu Artwork package, then you can make your desktop look very Ubuntu indeed.