I just received the following release from Mike Krampe at Siemens:
Update on S7 Vulnerabilities (Status June 13, 2011)
Despite recent news reports, Siemens latest software vulnerabilities are not caused by malware (like Stuxnet), but by a weakness in communication functions of its Programmable Logic Controller (PLC) product, called S7-1200. The vulnerability was discovered by an NSS Labs researcher and resulted in an ICS-CERT security advisory.