An interesting idea, but somehow I dont see it being implemented. In reality, your remote cant be far from your TV, so placing something in the remote that beeps when a button is pressed on the TV wouldnt be that effective, as the area it could be in surrounding the TV is relatively small. Also, how often would people use it? I for one would never use it, I hardly watch TV and I certainly never lose the remote.
I too thought about these long back,, but there are many things to think,, what if TV response to your voice. like if you want to see "Discovery Channel" if you just tell the name to turn to your desired channel.