Amazon vs. Google vs. Microsoft vs. Rackspace vs. ?

Nice article by Brandon Butler at Network World

Analysis: Like it or not, Cloud is finally upon us.  Enterprises, Service Providers, SMB, and more are finally evaluating, deploying, and utilizing cloud technology to reduce costs, improve agility, and provide strategic value to the business.  The battle between Google, Amazon, Rackspace, and Microsoft sounds like a great race, but the reality is Amazon is lapping the competition.  Amazon continues to innovate at a velocity that I have never seen in this industry.  Meanwhile, Rackspace is forced to play catch-up by developing on an immature platform (OpenStack) and must create new functionality to compete.  Microsoft seems distracted but continues to do a nice job transforming their company and I expect them to easily win the Windows PaaS segment.  Finally, Google is the threat of all threats as they have the scale to rival Amazon but they lack a successful enterprise track record.