One of my favourite blogs, University Diaries, recently pointed out a short article on George Gilder's recent prognostication that TV will die, and be replaced by blogs. While it's a nice idea, sorry, it ain't gonna happen.
Blogs, as a rule, comment on existing things; rarely do they create on their own (though the exceptions, such as Hitherby Dragons are among my favourites). This isn't a criticism; we have a need, in our hyper-aware society, to have commentary to set events, both fictional and real, in a context so that we can understand them for what they are meant to be.
TV, though Lord knows it has some serious problems, does create some wonderful new shows (though I confess sometimes that I'd prefer to watch them on DVD), both fictional and non-. Of course it creates a lot of drek, but Sturgeon's Law applies everywhere.
I digress. The point is, blogs can perhaps replace the Sunday morning pundit shows, and much of the commentary on CNN, MSNBC, Fox, et. al, but they won't replace, say, Picket Fences, or Monk, or Fullmetal Alchemist-- the experiences they create are so totally different in character, I just don't see how it can happen. Frankly, most Americans do not read for pleasure (incredible to believe, I know, but it's true), so why would they all of a sudden start? People want more than the passive, couch-potato-oriented entertainment they've had in the past, but that doesn't mean they're going to run to books or blogs.