Krugman, as usual, gets it right.
Who’s Serious Now? - NYTimes.com
Then people who actually understand budget numbers went to work, and it became clear that the [Ryan's] proposal wasn’t serious at all. In fact, it was a sick joke. The only real things in it were savage cuts in aid to the needy and the uninsured, huge tax cuts for corporations and the rich, and Medicare privatization. All the alleged cost savings were pure fantasy.