Do any readers know why there is typically only one cable provider in a given area? AFAIK, cable is treated like a utility, and as such its providers recieve certain benefits alongside being saddled with certain additional regulations. The general purpose of this was probably pitched long ago to some foolish legislator as, "it's the best approach, so that we don't have multiple sets of sewer / water / electricity / gas / telephone / cable lines going to each house." So cable providers get handed a de facto monopoly, in return for which they have to do certain things. They have to make basic TV (local OTA network) available at or below a certain set rate, and there are various other hoops they have to jump through.
The problem here, as I see it, is that Comcast is taking advantage of a monopoly that the local population has given to them, and abused it for the purpose of blocking out a potential competitor. Netflix isn't competing with Comcast online; it's competing with Cable TV, HBO, Starz, and all of the other content that Comcast sells to its subscribers. So yes, they of course want to squash Netflix into oblivion so that they can continue to upsell all of these services and make more profits. But using their monopoly as a cable provider - and hence an ISP - to do so is extremely dangerous. As others have pointed out, it's a very slippery slope when the only people who can reasonably deliver the content to you decide to start putting differential price tags on different pieces of content. Imagine Comcast Amazon, Comcast NewEgg, etc. Use their site or pay through the nose. Think you'll be able to research the best prices online in such an environment? Think you'll even be able to research all of the products available in the marketplace?
I think it's time that ISPs were forced - by regulation, and by virtue of them being utilities - to be independent from content providers. The alternative gets too ugly, too easily.