Virtualbox 4.0.4 + This week in linux

http://www.virtualbox.org/wiki/Changelog

X.Org guests: support X.Org Server 1.10 pre-release and Ubuntu 11.04 Alpha.

Hurray! compatibility with ubuntu 11.04 alphas :)

http://www.youtube.com/watch?v=aOD1dlPm6Wc