A small sample of comparisons suggests Hulu's versions are either genuine HD or, at least, streamed with much higher bandwidth than NF. I looked at Yojimbo and Fritz Lang's M for starters, and Hulu's presentation was obviously clearer and more detailed than that of Netflix.
This is potentially earthshaking for film enthusiasts.
A bonus is the possibility of streaming films not otherwise obtainable. The entire 18-film high definition Zatoichi package from Criterion can't be purchased at any price, it would seem. But you can watch it all on Hulu Plus, commercial free, for a low monthly fee.
The future has arrived. Wow.