And there's more good news - although the bulletin comes with a maximum severity rating of critical, that only applies to PowerPoint 2000.
For other affected versions (XP, 2003 and 2007), it's only considered important. The same applies to PowerPoint Viewer 2003 and 2007.
The exact nature of the issue will be disclosed next week, but it seems likely that it is another 'malformed document causes buffer overflow with potential remote code execution' problem.
The PowerPoint update will be available via Microsoft Update but not through Windows Update.
Microsoft officials have said there will also be the customary update for the Malicious Software Removal Tool. It seems likely that the junk email filter will also be updated as usual.
At least one high-priority but non-security update is also expected on Tuesday.