Re:Only 1 problem..
Well, slightly more than one problem really. I make all sorts of "gestures" in the direction of the TV when I'm losing at various console games, and I don't even want to think about what would happen if you tried to play a Wii game.
Ok, so they could allow you to turn the feature off when you didn't want accidental, or other peoples, or gaming gestures changing the channel for you. Then you'd have to reach for the remote to re-enable it, which kind of makes it completely pointless.
Factor in to that the TV changing channels when you're simply trying to explain the plot of a film to your other half for the hundredth time and this feature seems to be the most pointless inclusion since Britney's underwear drawer.
Techies can be great at inventing stuff but this is one of the cases where someone needed to go, 'err....hang on a sec'.....