...when it comes to true distributed systems interoperability.
We need truly openn way to temporally decouple services on SOAs and doing that requires a substrate to provide reliable asynchronous messaging exchange. Hopefully AMQP will get traction and get done pdq. The world needs this yesterday. It amazes me that such a critical piece of plumbing has taken this long to bubble up on the Web on but there you go.
Truly open, interoperable protocols must come before the cutesy don't-worry-your-pretty-little-head-about-it-and-just-drag-and-drop APIs, if lock-in is to be avoided and open innovation fostered. Think SMTP. Think HTTP 1.1. Think XMPP.
Note to API-centric developers who read a lot of stuff vendor-driven about interoperability via their "open, standards based APIs": "No". JMS, WS-Relia*, Biztalk etc. do not do what AMQP sets out to do.