Ubuntu 9.04 has now been released in Desktop, Server and Netbook Remix (NBR) versions. The NBR version supports a range of Netbooks including the Asus EeePC range.
A list of netbooks supported and known issues can be found here – https://wiki.ubuntu.com/HardwareSupport/Machines/Netbooks
Download Ubuntu 9.04 NBR from http://www.ubuntu.com/getubuntu/download-netbook