I'm developing something now that implements a push client, and I keep seeing people getting excited about XMPP for publish-subscribe type things.
The slide deck that keeps getting press lately is here: http://en.oreilly.com/oscon2008/public/schedule/detail/4359
It really seems to me that using XMPP (which is a stateful chat protocol) for RPC might be the wrong approach. Have the XMPP advocates just re-invented message queues?
In the OSS world, ActiveMQ exists, so does AMQP. MQ theory is very old, having been used for decades for things like financial systems.
Am I missing something?