You could certainly do something with websockets but it may involve making substantial compromises.
With TVs you have the added issue that people probably don't want to replace their whole TV every couple of years just to upgrade the graphics or whatever.
This is brought up often but it appears some basic multiplayer is possible over websockets (I've written a very simple game using them). If UDP is that necessary, people will push for it and we'll eventually see it (or something equivalent) in the browser.
> With TVs you have the added issue that people probably don't want to replace their whole TV every couple of years just to upgrade the graphics or whatever.
This is turning out to be less of the case though as older PC hardware can still run newer games. The need for graphics is no longer growing faster than the resources to power them. This is especially noticable in the indie game market where rather simple graphics games have become very popular. Even high-end games don't "need" new power as much as they once did, the PS3 is what, 7 years old now?