Microsoft will omit anti-virus protection in Vista, the next version of Windows, which it plans to ship late this year. As with previous versions of Windows dating back to Windows 2000 at least, Redmond is promoting Vista as a landmark improvement in Windows security.
For unspecified business (not technical) reasons, Microsoft will sell anti-virus protection to consumers through its OneCare online backup and security service.
Symantec, though its assisted enquiries from investigators, has said it would rather take on Microsoft in the marketplace than cry foul to regulators over Microsoft's entry into the consumer anti-virus marketplace. McAfee has made no suggestion it's about to object to Redmond's encroachment on it traditional turf, either. So it seems Microsoft has either decided anti-virus technology is better delivered as a service or else figured out that's a better business model to pursue.

