The vast majority of Web applications will eventually run on platform-as-a-service, or PaaS. The shift will be slower than to infrastructure-as-a-service (IaaS) because finding the perfect PaaS fit will take effort, and there's significant loss of control over hardware and software. Many IT departments will resist. But it will happen, so to help you evaluate options and plan a migration strategy, we sent out a questionaire with more than 70 factors to consider to major PaaS providers. You can download a full set of responses at ourInformationWeek PaaS comparison site.
http://www.informationweek.com/cloud-computing/platform/why-paas-is-the-future/240152659