Actually, you can now host Windows Servers on Azure. This was in beta for a while but MS just announced the new Azure code release on June 7th, which means you can now run Windows Servers on Azure and its fully supported. There were a lot of other features that came with the new version also. You should check out the intro by Scott Guthrie for a good summary of what you can do with Azure. http://www.meetwindowsazure.com I watched it live but I'm sure it is still available for viewing.