Cheaper-TV take: PBS provides a valuable public service, but I also understand the need to reduce the deficit. The fact of the matter is, there isn't a huge audience for thoughtful tv. If given the choice between watching a Nova show about Unlocking the Mysteries of the Stonehenge or watching MTV's the Jersey Shore, most people will watch the latter. Advertisers will spend their money on the program that gets the most eyeballs. This will leave very little funding for educational shows.
Here's a thought... fund the Corporation for Public Broadcasting with the proceeds of government spectrum auctions. In 2006, the government took in 13.9 billion dollars in spectrum auctions. Some greedy politicians are trying to help fund elections with some of this money (10% or 1.3 billion). I would rather these funds be used to fund PBS and it's educational programming instead of funding more political ads that serve no public good.