Live sports are not the last stronghold.

There's a whole slew of shows which would whither and die without a cable subscription model.

Think Food Network or Discovery or any show which isn't a serialized story model. Would you actually buy a season of Mythbusters?* I watch those shows all the time, but usually when I'm just browsing. I'm not sure I'd actually buy them ala carte.

BTW NFL and NCAA aren't holding out on streaming. The rights to internet broadcast games are tied to their traditional cable and broadcast deals with cable providers and the Comcasts and TWCs of the world are locking in those restrictions. MLB is the only one who kept their streaming rights.

* Note I'm not saying no one would - but I don't think enough people would