In an action usually reserved for presidential inaugurations and other major news events, Saturday's Patriots-Giants game will be simulcast on three television networks. Supposedly the NFL Network, which no one has, was pressured by Congress (which apparently doesn't have anything better to do) into putting the game on free TV nationwide. CBS and NBC will simulcast the NFL Network feed of the game. I guess CBS gets to show this because if this were a Sunday afternoon game, they'd have the rights to it. I have no idea why NBC is showing it too -- maybe they have some claim on all over-the-air night games? Beats me.
This is not the first time NBC and CBS have simulcast a football game, by the way. Super Bowl I was also simulcast by the two networks -- CBS had the NFL broadcast rights and NBC had the AFL rights, so I guess they thought that was the best way to deal with it. They never tried it again, possibly due to economic reasons, and also perhaps because the two tech crews were at each other's throats by the time the game came around. I recommend the book "Going Long" for its AFL history and a look at that game.