Here's an early draft of an attempt at describing a purely RESTful API to ActiveMQ using AtomPub. Mapping a message broker to REST and AtomPub turns out to be much harder than it looks.
The trick I've used in this draft is that consumers subscribe by creating a new subscription Entry (as a new Entry in the subscriptions Collection) which times out eventually if the consumer goes away. Then each consumer consumes from its own Feed, so that things are nicely load balanced etc.
As usual - any feedback most welcome