If nothing else, it's fairly easy to circumvent for Comcast: Just say that Xfinity isn't an internet service, it's a ComcastNet® service that just happens to get delivered over the same cable as your internet connection. Figleaf: "You can buy a Xfinity/ComcastNet® subscription without an internet connection.".

Where it gets icky is when Hulu suddenly doesn't count against the cap, but Netflix does, and the deal Hulu got isn't available to Netflix.