[izak30]

They won't have to make theirs open, or join OpenStack. All they would have to do is write a set of binaries that translate commands from one to another, and translate return values. Presumably some hackers will sort this out and open source it.

[jnoller]

boto, libcloud, etc, etc mostly support talking to multiple clouds. The API is far from the hardest part of migration - it's actually pretty simple in most cases, unless that vendor picks something like SOAP.