Isn't it obvious what Comcast is really doing? They see the usefulness of high speed connections and how they will allow people to view TV and movies on demand. They don't like this as it cuts into their cable profits. Hence they are capping the service to cripple the usage of IPTV and better promote there crappy old delivery system, ie. cable.
It's all just a big anti-competitive ploy being disguised as a CAP!