I've heard nothing but bad stories about run-of-the-mill DSL. My brother had a lousy experience with it here.
Sandy has Netflix streaming to the TV here. It's mostly shit. Shit, shit, shit. They get almost nothing new or good, ever. If you want the good stuff from them, you have to get it the old way: DVDs in the mail. Then half of what you stream has some really shitty encoding. The word of the day is: shit.
My brother has a Roku box. He has a bad experience with that because the internet speeds are not constant. Overall he gets good throughput, but at times it drops down, and the playback freezes. This is not the DSL I mentioned above. He got rid of that in a hurry. He has Roadrunner, which works like a dream at my mother's. It must be a neighborhood or infrastructure thing. A better buffer in that Roku would probably solve this.
As much as streaming is becoming the norm, I can't see it displacing cable and satellite TV anytime soon. Streaming has a long way to go, and some setbacks to contend with, like the constant pernicious attempts by the big ISPs to meter your internet service. Edit: For example, Ren's neck of the woods.