Just a quick heads-up, though I'm sure everyone has seen this already. Microsoft has release a critical patch out-of-cycle as of today. From the SANS link below, "The update addresses a vulnerability with RPC calls which can be referenced from SMB connections." It's implied that there is a remote code exploit for this bug, and the out-of-cycle nature of the patch suggests that there may be an emerging or active threat.
Primary links:
http://www.microsoft.com/technet/security/bulletin/ms08-oct.mspx
http://blogs.technet.com/msrc/archive/2008/10/22/advance-notification-for-out-of-band-release.aspx
http://isc.sans.org/diary.html?storyid=5227&rss
Additional coverage:
http://voices.washingtonpost.com/securityfix/2008/10/microsoft_to_issue_emergency_s_1.html
http://securosis.com/2008/10/23/microsoft-critical-update-today-link-to-4-pm-et-webcast/
http://www.securityfocus.com/brief/844?ref=rss
