Hulu is customizing ads
dannyok.com
dannyok.com
What would be really killer for them is if they integrated Facebook. They should offer something along the lines of additional content or earlier access to episodes for people who become fans of Hulu on facebook or something. Almost zero cost to the user in return for a small bonus, and Hulu gets tons of demographic information.
Most HN readers probably wouldn't go for this, but I think the average person would.