This would create more problems than it solves. Cables are normally superior to wireless in terms of quality. Compare a wired microphone to a wireless microphone. The wired one tends to be clearer.

Next is the cost. Firstly, you are spending a lot of money on the tv. Now you would have to factor in the adapters that the average person would have to buy in order to use wireless vid and audio. Game consoles, media players, speakers, and cable tv boxes would mostly have to have special adapters that will then most likely sell for much more than a cable, as now you would need to have pcb's as apposed to copper wire