I read every day about the need for cloud computing interroperability between providers. Just about all of it is talk.
Providers claim they pay attention to this point, however the only major move beyond just straight API's is the Google Secure Data Connector
release the other day.
I really think interroperability between providers is going to have to be defined, and built by the masses. The developers who rely upon the cloud for their infrastructure will have to build the layers of interroperability between these provders to meet their needs.
I love Amazon EC2 and it is definitely meeting a lot of my needs in most areas. However through my research of other cloud providers I am seeing other players have focused on areas that Amazon has not.
So as my Cloud Migration approach stabilizes for my company I am exploring how I can continue to meet demand beyond Amazon EC2. I already started storing data from Amazon on the Mosso cloud using Jungle Disk.
There is a case of a provider stepping up defining interroperability and building a tool for it.
I think we will see many developers step up and build a wide range of tools and layers for interroperabilitiy between the clouds. I don't think its likely you will see the providers doing much of it, it is in there best interest except they are too self centered.
Hopefully soon we will see a wide variety of tools for cloud interoperability pop up and a marketplace for these tools to be bought and sold.