I'd like to go out on a limb and say yes, TV is making us dumber, but not in the way that lots of people have stated here. I'm of the belief that the news and all those "expert" channels are making people believe everything they see and here. When someone turns on O'Reilly (sp?) and listens to him rant about one thing or another, they take that as the truth and as news.
CNN, FOX, MSNBC, all of them are biased and tell spins on every single story they sell to us. If everyone goes around believing it all, then they allow themselves to be twisted to the sellers whims. This all amounts to us not actually knowing anything, and going by what we're told. We don't question anymore, we just take it all in stride, like we're all apathetic. I am of the fortunate few who haven't really been affected by the crappy economy. If I had lost everything due to what some rich CEOs did, I'd be extremely pissed! I actually sit here and wonder why there haven't been riots or threats or anything else of the like, due to all the money that's been lost.
Most of the world has become a slave to the media, TV especially (because we all know you can't believe anything you read on the internet). It amazes me to this day that people just sit back and "hope" things will change.