The NSA is somewhat open about the massive amounts of computing power they have available: http://nsa.gov1.info/utah-data-center/

Lots of goodies on this public site like "This [compute cluster] will give us the capability to break the AES encryption key within an actionable time period and allow us to read and process stored encrypted domestic data as well as foreign diplomatic and military communications."

Obviously leaked documents and other media reports contain much scarier revelations into what the NSA is capable of, but I thought I'd post what they acknowledge since it's safe to assume they're capable of much more.