In that regard, Stuxnet is not new. It has actually been around a while and started receiving notoriety this summer. It continues to be analyzed and more fascinating information continues to be found out about it. If I recall correctly, yes, the USB exploit was the icon issue, one of the zero-day exploits in windows that this used.
So far it looks like it scores in several firsts in regards to its complexity and scale.
1 - it is probably the most complex piece of malware ever discovered.
2 - it is suspected as having been created by a national govt entity and used as a weapon against a specific target.
3 - It targets, industrial embedded computers (PLCs) that are (typically) significantly more hardened in both their hardware and software compared to conventional PCs
4 - it successfully uses the Man In The Middle attack to get around encryption certificates, using certificates from a "trusted" entity.
5 - it uses multiple (4) zero day exploits, including two previously unknown ones. Makes you wonder about the push to release the Windows source code a few years back.
While, in my opinion, it doesn't represent a direct threat to the commercial PC arena, it does take computer malware to a new level.
