Siemens has isolated the virus on a test system to carry out more extensive investigations. Based on previously analyzed properties and the behavior of the virus in the software environment of a test system, this does not appear to be the random development of one hacker, but the product of a team of experts. The company suspects that this team is comprised of IT experts with corresponding engineering knowledge of industrial controls based on the virus deployment in industrial production processes.
The extent of the threat to industrial systems still posed by Stuxnet following the implementation of the security updates will, however, remain uncertain until further investigations into the Trojan and its mode of operation are complete. Siemens does not yet have any leads as to the source and origin of this malicious software, but analyses are ongoing.
This whole Stuxnet business is highly intriguing. For those not following it, I highly suggest Googling around about it. Bullets in the cyberwar are certainly whizzing by in all directions these days...