Quick question, "why is windows not suited for deployment in the cloud?"
Take a look at amazon's pricing. Next, take a look at rackspace linux and windows pricing.
Do you notice anything? A keen observer might see:
#1 Windows costs between 1.5x - 2.6x more than linux per compute cycle.
#2 Windows is in BETA for the rackspace cloud.
Now some folks might argue that this cost is offset by fact that windows servers are more managable (after all, you get a nice pointy clicky user interface right?). Those folks should try to push an update to 100 windows servers using the pointy clickly technique.
Any administrator worth their salt is going to use scripting and automated deployment techniques which is where linux really shines. Windows as a desktop platform is pretty good (although ubuntu is catching up, but it windows as a server platform still suffers from it's high TCO.
All this having been said, I guess I'll restate my subject in a slightly different way:
"Windows is very cost efficient or technically capable for creating distributed systems"