There's various wireless HDMI extenders, and I think some that tunnel the signal through the power lines. You'll still need a receiver of some sort near the TV, though it might not be as big and bulky as a set-top box.
I use a Brite-View BV-2322 between my TiVo and my equipment rack. It can send up to lossless 1080p with audio, and sends IR in the other direction so the remote control signals can get back to the equipment. The catch is a limited range. My transmitter and receiver are 16 feet apart with a nearly unobstructed line of sight, but they still occasionally refuse to sync up at first (maybe once a month). When they work, the picture is perfect; when they don't, it's just a blank screen with no useful diagnostics.