For more on why this makes sense, see: "PaaS as a satisfying and success-ready hobbyist platform" (with Google App Engine as the primary example) http://stage.vambenepe.com/archives/1014

Apparently it's not only for hobbyists... it's the leading favorite amongst enterprise CIOs too, as seen in this Morgan Stanley survey which just came out last week: http://goo.gl/LcbS