Technology: TV over phone lines? Can it fit?

Here is an interesting NYT's article about AT&T and Verizon both trying to grab some of the cable market with TV over phone lines. Just one question I have - if cable internet is already WAY faster than DSL, how do they expect to fit high quality video next to phone and internet services and make it competitive? I'm sure they have some solution - I'm just a little skeptical. But if it'll help drive down cable TV/internet prices, I'm all for it!!