Not only did Stuxnet use four zero day exploits, only two of which were unknown; more analysis by actual experts has resulted in exactly the opposite conclusion of the media.  Although this was certainly put together by a group of people with a wide knowledge base concerning their target, a nuclear fuel refinement facility, the actual programming displays some basic errors with regards to the construction of a computer worm intended to hide from detection.  Either they were unaware of some old cloaking tricks better than what they chose to use, or the authors intended the worm to be discovered.  Considering the evidence all together, the worm was probably written by a small middle-eastern government in a hurry with a strong motive to delay Iran; which seems to implicate Israel.  However, Iran's facilty is still not running months after the discovery of Stuxnet, so the one that was found may have been a distraction for an even better cloaked version still hammering away at it's intended target.  It was a very precise weapon, as well, very tightly targeting only the particular facility it intended.

If any GNU/Linux distro has four unpatched zero day exploits at the same time, I'll eat my hat.