This isn't news, except to me, and I guess you, otherwise why would you be reading this?
Full screen flash video sucks on my eeePC with ubuntu (again not news)
but pointed out that if you have/create a /etc/adobe/mms.cfg file, you can enter the following line: at Penguin.SWF
and then you can effectively use GPU acceleration which makes full screen flash run much better.
Hulu is still choppy, which is due to (I suspect) its high quality data intensive stream. But youtube is much better.