'Political junkies' and liberals will watch MSNBC, and angry, old right-wingers will watch Fox.
Ideally, in the future, you'll just pay your cable company for the stream, which you'll be able to watch and manipulate through whatever means on whatever devices you like.
For most of the millions of people who watch TED videos at the office, it's a middlebrow diversion and a source of factoids to use on your friends. Except TED thinks it's changing the world, like if 'This American Life' suddenly mistook itself for Doctors Without Borders.
CNN's problem goes to its very core and to the identity it's sought ever since the rise of Fox News, on its right: CNN is the channel for people who don't want to watch the other channels! That's a stupid strategy.
CNN will always be the channel people turn on when wars and horrible disasters happen. The 'trick' is getting people to also want to watch it when there aren't hundreds or thousands of people somewhere in the world currently in mortal peril.
It's been possible for years to use a PC to watch and record over-the-air television broadcasts, and unencrypted cable television tuners have been available almost as long. But for a long time, you could only watch copyright-protected channels with a cable company-leased box.