What's On The Cloud Vs. What The Cloud Is On

No one but Microsoft would *run* their cloud on Windows. That's a big
distinction. Amazon will run Windows for you. On their
non-Windows-based cloud.

Meanwhile Microsoft will come up with a new OS for their cloud. Will
that be for everyone's cloud. Or just their cloud? Is this another
attempt to carve out a proprietary product that no one else can
(easily) emulate? As in "my code is written for Microsoft's
proprietary Windows Cloud OS. It won't run on the Windows Server that
Amazon supports."

http://www.microsoft-watch.com/content/web_services_browser/ballmer_looks_to_the_cloud_and_says_windows.html