Without export as well as import, VMware is in the pivot position
Joe Emison makes some very strong points and he's right, as far as the state of the art goes today in cloud computing. It's difficult to do hybrid and best stay away from ambitious hybrid interactions, at least until it becomes a surer thing. But it doesn't have to be this way. The import mechanism, I believe, is based on the Open Virtualization Format, a DMTF standard agreed to by multiple vendors in 2010. With a little more work, a standard could be established for export as well. Without an export standard, VMware is going to be the party that makes import/exporft easy, provided it's a VMware cloud.