Alex Freedland had an interesting opinion post over on the Mirantis blog about OpenStack's direction. Not only does Freedland believe that OpenStack, a project that started out as a "build-your-own-AWS-like-cloud" project, is going to become more than just an IaaS competitor, but he also believes that when OpenStack starts competing with PaaS vendors, the vendors won't stand a chance.
I think he's right about the evolution towards PaaS-like capabilities for OpenStack. The signs are all there in the Havana release. I'm not sure whether OpenStack will be a major problem for the PaaS vendors though.