He said that Microsoft has listened to suggestions from users who demanded better support for non-Windows machines in the Operations Manager software. Ballmer stated that support for running Linux-based virtual machines will be added later this year in a service pack for the Virtual Server software.
Although the current version allows someone to run Linux or another operating system, Microsoft plans with the update to add support when customers run into trouble with a non-Windows operating system.Ballmer also showed Microsoft Operations Manager controlling Solaris servers.
More info about Ballmer's speech at CNET