I installed Lubuntu 10.04 Beta1 on an EEEpc 900A today. That's the lightweight LXDE version of Ubuntu.
In short: all of the software and hardware works. more work is needed on English-French translation.
Here's how it went:
Quick download using uTorrent (windows), moved the distribution to a USB-flash-drive using unetbootin. The download was 396MB - much smaller than Xubuntu. The machine booted up quickly and easily. Wireless internet with Chromium browser worked effortlessly in the "live-usb" environment. I installed the system to the hard drive - the machine spent a substantial amount of time downloading language files and then spent a fair bit of time "running dpkg" - this process took 5-10 minutes more than expected. (I've installed Mint, Xubuntu, Ubuntu, and Masonux on eeepc machines before.)
Abiword and Gnumeric seem problem-free. Chromium browser works great. Lubuntu 10.04 seems ready to go, but there are a couple areas where it didn't live up to my highest hopes:
a number of menu items are in English rather than French. The file manager is in English, and Chromium defaulted to English even though the OS install language was set to french.
in contrast to certain non-Ubuntu OSes/distributions, Java and Flash require a separate download. Ubuntu One is another app I would have liked included by default.