Ask HN: Do any 3D TVs allow watching two different streams?

So here's a novel idea (I think). All the 3D TVs that I've seen so far employ active glasses for shuttering every other frame. It seems like it would be a fairly minor hardware tweak to allow these rigs to add the capability of showing two completely different 2D image streams to two groups of viewers. In other words, people with their actives glasses switched to "A" could watch NOVA while the kids are playing Xbox on the same TV. Obviously, audio is a problem, but the glasses are already active, so slapping a Bluetooth audio receiver in there and some ear buds should solve that. This seems like a vastly more useful feature for me than watching the occasional 3D movie. Has this been done?