Now, of course that doesn't mean the networks like it, or will agree to a contract like that. They should though, because they'll never get more than that out of me per month, and I see cable becoming increasingly irrelevant as streaming becomes more popular.
But as pointed out elsewhere Hulu is a trial service and still working out their model. It has quite a few shows but its totality is actually quite small. They're controlled by the networks and if you follow their TOS you should only be able to watch their shows on a pc NOT on a TV.
Netflix's service is awesome but again quite limited.
Sports is completely ignored in your model. ESPN makes $2-3 per cable subscriber whether you watch them or not. This equals about 1 billion (no joke) a year in revenues for them. So just to get ESPN it would cost about ~%10 of your viewing budget. Now its not just ESPN every network thats older than 5 years old gets a cut of your cable bill. Let alone the fact that you can't stream most local sports over the internet at this point.
I see both sides of the argument and I thought as you do that cable is becoming more irrelevant. Heck on Monday the UFC's Roku channel launched - which allows users to bypass cable for PPV events. My company built that. But the truth is that the TV Networks are pretty inextricably tied at this point to the cable operators. Internet delivery of on-demand content at a reasonable rate doesn't yet make sense.
You left off "...for now." Hulu is on record that they'll be moving to a PPV model for certain shows. The days of completely ad-supported Hulu are numbered.
Never going to happen. They'll do ala-carte pricing for on-demand content but no major network would go for a fee this low. I shouldn't really say never, it could happen but it would be very near or even above what you pay for cable now.
Realize that a large portion of your cable bill already goes to the networks - and the networks get a large chunk of chedder in ads. There's no way $30 a month for "all shows" could come anywhere near making up for the money a network makes with cable. For Apple to offer this service it would cost you more then you already pay for cable.
Realize too that the large cable systems are actually looking at providing this service with an initiative called TV Everywhere.