And SOLELY because I enjoy playing the devil's advocate every now and then, I did a bit of googling on the opposite end of the spectrum:
http://www.psychologytoday.com/artic...es-you-smarter
http://news.cnet.com/8301-1023_3-10457411-93.html
http://www.filmgecko.net/2010/09/20/...ringe-mad-men/
http://www.edukey.net/2008/10/30/if-...e-you-smarter/
Some scientific, some not so much.

I hardly watch TV myself so I don't have a dog in this fight. I guess I just want to point out that you can find studies to support anything you want if you look hard enough. I could just as easily come up with sources to support why TV makes you stupid.
I say do what you enjoy. Life is short.