Comcast's announcement comes a day after HBO joined the experiment, and five days after the addition of Starz. The other 17 new participants are A&E, AMC, BBC America, DIY Network, Fine Living Network, Food Network, Hallmark Channel, HGTV, History, IFC, MGM Impact, Sundance Channel, WE tv, E! Entertainment, The Style Network, G4 and Fearnet.

TV Everywhere is a set of "principles" jointly developed by Comcast and Time Warner Cable. Unlike existing video portals such as Hulu and YouTube, TV Everywhere will be available to paying cable subscribers. No online-only option will be available for the service.

This may seem like a boneheaded move to Internet-savvy TV watchers, but content providers are jumping on because there's little to lose. As long as people hang onto their cable subscriptions, networks will retain precious licensing fees. If shows begin to reap , that's even more money in content providers' pockets.

But that mentality hinges on whether people do, in fact, retain their cable subscriptions. There's that people are dropping cable for online video, and often times money is the motivation. It's not that people would rather watch on their computers than on a televisions, it's that they're tired of paying $40 a month for a load of channels they don't watch at all. Alas, the viability of a la carte pricing is a debate for another day.

As for TV Everywhere, I can't wait to see whether it pans out for Comcast and Time Warner. A nationwide trial of 5,000 customers will begin in several weeks.