Most HDTV's from the past 5 years should do both 720p and 1080i. The cable company will just pass through what ever the channel is broadcasting. So if it's 720p or 1080i the cable company isn't going to change the format.
Just because a network has cameras capable of HD doesn't mean they have the equipment to broadcast it. Networks have to spend $100s of thousands to upgrade all the equipment to be able to broadcast in HD.
Just because a network has cameras capable of HD doesn't mean they have the equipment to broadcast it. Networks have to spend $100s of thousands to upgrade all the equipment to be able to broadcast in HD.