The elephant in the T.V. room:
Who is providing most people with their broadband internet connection required to use Hulu in the first place? That's right, the same companies that are traditionally charging us for cable, satellite, or fiber optic t.v. If a "critical mass" of people switch to services like Hulu and cancel t.v. services enough to tip the revenue scales, then these companies will just compensate by charging higher prices for internet access, and possibly phone services if you do not subscribe to their T.V. package.