One if the most interesting features that I have read about on the XBOX 360 is that you will be able to view other peoples in game experiences live over LIVE. You can watch tournements or if you do not feel like playing but instead you want to chill out and want to stay connected, just jack into your buddies game. This LIVE TV feature has not been detailed extensivly in the media and I am uncertain if it would be supported in every game (it would be cool if you could watch someone playing , it would be like watching a horror movie) but it is going to be there.
The XBOX has all but killed my TV viewing with all but a handfull of exceptions. All of us are busy and have a limited window for entertainment. So why would I watch something over interacting with something or someone? If you have not noticed recently also, there almost nothing but crap on the tube anyway. XBOX 360 is only going to push me further away from the TV medium and further into the HD era.