At this time, there is no HD service available in any of the residence halls. The University contracts television service directly from Cablevision, and all campus TV jacks are served from one central location. The package we receive only has standard definition channels, and that is what's broadcast to the campus. Most likely, if you connected a cable box and it worked at all, you'd receive the same lineup as if you ran the cable directly to your TV so I don't recommend it.
(That being said, if you try it and get different results, I'd be interested to hear about it.)