Although I think windows and mac os x can be together, and there is nothing wrong Microsoft uses Mac since they have Microsoft Office 2008 for Mac. In a Microsoft Keynote in Louvain, Belgium, there is a MacBook Pro appeared in the show. And here is the other photo when Steve Ballmer is on the stage, the MacBook Pro is still there. May be there are running Windows on Mac using Bootcamp or Parallel.

[via Flickr]