Open Stack

So my sense from responses so far:

No one is doing unified SDN solutions across clouds and no one really
wants to.

Consensus is just treat each network island like another remote DC and
use normal VPN type stuff to glue them together.

( nod to http://romana.io an interesting looking network and security
automation project as a network agnostic alternative to SDN for
managing cross cloud policy on whatever networks are available. )

-Jon