Hulu is a great site right now and it turns plenty of profit (as seen above). I figure when you can afford a Super Bowl commercial, you are fairly well off. I used it for a year and a half instead of buying cable and I check it at least 5 times a week to see episodes I may have missed from some of my favorite shows.
That said, if a payment model were injected I would abandon the site in a heartbeat. So would a huge portion of Hulu viewers. It would probably destroy the site.
So in conclusion, please go DIAF Mr. Miller, before you enact a terrible idea that destroys an awesome site. Thank you.