I just blogged about how to get Ubuntu 9.04 up and running in VMware Fusion 2.0.4:
http://blogs.vmware.com/teamfusion/2009/04/ubuntu-904-on-vmware-fusion-2.html
This might be useful for people who want to try it out before our official support for this guest.
David Liu
Product Manager
VMware
For those looking for an automated solution to installing VMware Tools in Ubuntu 9.04 Desktop Edition which incorporates information in David's Blog and additional changes that need to be made have a look at: