Taken from <http://www.informationweek.com/news/cloud-computing/infrastructure/showArticle.jhtml?articleID=229300184&subSection=News>

Microsoft Azure Named Fastest Cloud Service

CloudSleuth's comparison of 13 cloud services showed a tight race among Microsoft, Google App Engine, GoGrid, Amazon EC2, and Rackspace.

 

In a comparative measure of cloud service providers, Microsoft's Windows Azure has come out ahead. Azure offered the fastest response times to end users for a standard e-commerce application. But the amount of time that separated the top five public cloud vendors was minuscule.



I think the IVS (independent software vendor) space will be very interesting to see what platform is broadly adopted.  Will watch with great interest.