Having missed the Advance Notification for Microsoft's May release of Security Patches, it might have been possible to miss the actual release of the patches, with just two bulletins released, targeting only a small subset of Windows systems and Microsoft software, with only users and administrators of Windows Server 2003 and 2008, and Microsoft Office users affected by the updates.
Both bulletins deal with remote code execution weaknesses that were not publicly reported on prior to bulletin release. Only the first bulletin, for the Windows Internet Name Service (WINS), was rated as Critical. The other, for the PowerPoint component of Office, was rated as Important. Differentiation was made based on the perceived ease of exploit development and overall exploitability of the vulnerabilities being patched.