When I studied cryptography in college, our professor said matter of factly that the NSA is likely at least a decade ahead in terms of known mathematical breakthroughs, but perhaps he was biased toward thinking that because he was in the field during the 1970s breakthrough that Schneier mentions. It seems more feasible that the breakthrough is in engineering and technology, but hey, I guess it's good to know the boundaries of mathematical reasoning can be pushed (hopefully, those gains will be available to the rest of the world for non-spying means)
edit: Case in point, Schneier's 2007 post that's now on the front page
https://www.schneier.com/blog/archives/2007/11/the_strange_s...
Schneier describes a random number generator, released as the standard by the U.S. government, that he concludes was likely back-doored through NSA intervention. This hypothesis was made by two independent researchers in the previous months, and others had suspicions a year before. My point being: in terms of open encryption standards, it's very amazing that the NSA (or any private entity) can make a purely mathematical breakthrough that's well-ahead of the field.