My father told me when he was young, he visited Oak Ridge National Labs on a trip, and while there, they told him they had satellites that could read the print on a newspaper. At the time, it wasn't classified information; it was just something that nobody knew. Approximately 15-20 years later, satellites with that capability became well-known. This indicates to me that top secret technology is probably somewhere around 15-20 years ahead of what the general public knows about. This may be less true today than it was back then since nowadays the equipment and factories to develop state-of-the-art technology run in the billions of dollars.
Where I'm going with this: is it reasonable to assume that "future technology" 20 years from now could crack AES-256 or PGP? If so, it seems reasonable to me that the NSA could already crack today's encryption for high-priority data. Add that to the fact that they tend to hire the very best experts in the field (mathematicians and cryptographers) and it doesn't seem entirely unreasonable to me that their decryption technologies are pretty good. Of course, I'm not talking about better technology in a brute-force sense; it would still be impossible to crack 256-bit encryption. I'm talking about algorithmic weaknesses.
But then again, I have only a basic knowledge of cryptography. Would any experts like to comment?