Folks I recently came across this site on codeplex - http://btsazureadapters.codeplex.com
Where a hard working Danny(not sure of further details) has created a send and receive adapter for the cloud.
The adapter surface and publish the required information into the cloud so for e.g. your endpoints show up publically in the .NET Servicebus domain – we can do this through the apis, but it’s nice to have them all wrapped up.
There’s even some great piccys as well (just over look the ‘Microsoft Confidential’ at the bottom :-| - I did ping him over this.)
The adapters are WCF based adapters, meaning they will run in or outside of BizTalk using the .NET LOB Adapter SDK Framework.
As a Plan B to this – you can always use a Custom WCF Adapter with the basicHttpRelayBinding or netTcpRelayBinding to punch through to the cloud.
I reckon this will be a very exciting area going forward…keep your eyes peeled.
Go and grab the bits and start playing… :)