I just got my invite to the Hulu beta yesterday and am diving into it now. My first impressions are that it's pretty elegant. Very good video quality, clean design and nice flash player. You can even edit your own clips and just post the piece you want.
As for content, there is a bunch of current NBC and Fox shows (The Office, Heroes, Friday Night Lights, The Simpsons, House, Prison Break, etc.), some old shows (Simon & Simon, WKRP in Cinncinati) and even a few movies (Sideways, The Jerk, The Breakfast Club).
And now for your viewing pleasure, my current favorite network show:
And one of my all-time favorite network series (may it rest in peace):
The problem? They don't let you easily change the size of the embedded player, I had to go in and manually edit the object width on each of the videos above to get them to fit...