Comcast pulled quite a bluff, but I don't see how they can win in the long term. As a Comcast subscriber, I'd more than happy to switch to a different ISP if Comcast starts to limit access to Netflix or any other content provider.
How many broadband ISPs are there in your area? In many areas, there are no more than two. If they both adopt this policy, without net neutrality you're out of luck.