Got my E-350 powered notebook this week and it's amazing. With the Catalyst, everything works, from suspend, to setting up external monitors through HDMI etc. although right now, I am running Ubuntu 11.04 with Unity and the opensource stack through xorg-edgers. I. LOVE. MY. NOTEBOOK.
So, which one is it? HP dm1? BTW, what do you have to say about the CPU performance? Have you tried anything a bit more cpu-heavy?