Not really. I responded to John's comments in the previous Social Security post, but think it's important enough to move to the top.
John, I don't think it's at all a Ponzi scheme in the traditional definition of that term. I think it was designed to be tinkered with over ongoing generations to keep up with the ebb and flow of american generations.
In the 80s, politicians realized that if left unchanged, it would run out of money. So, they raised the amount of money that people currently put into it. This caused it to have a growing surplus. The surplus will stop growing in approximately ten years or so and then will be tapped to pay the benefits of the so-called "greatest generation. Right now, if the government did nothing, it would still last well into the 2040s. If they tweak it minorly, it will likely go on for decades more. Paul Krugman has more.
And, yes, I might have some of the years slightly off, but this is the consensus of nonpartisan experts. They key, of course, is the nonpartisan part.