Good question and I asked myself the same when I wrote my original response. It's difficult to get a truthful answer of what someone would pay unless they are actually paying but I'll try.

My DirecTV was ~$75/month with taxes which cost me around $2/hour based on 1hr a day. I switched to Hulu because my costs went from $75 to $0. I'd probably be willing to pay up to $30/month commercial free or $15/month with commercials.

I do wonder if Hulu will seriously be able to compete with cable when Comcast is on the board.