I have been looking at JBoss Cache (Tree Cache specifically, not pojo cache), as a default way of deploying from BRMS to runtime systems.
This mean the runtime system, as well as the -core jar, will also have an optional dependency on jboss cache - and be able to be hooked into a named jboss cache on the network. The BRMS (or anything) can then progressively update rulebases with binary packages. Each runtime (rule-agent) also has a local persistent store, so servers can be cold started without BRMS or cache "cloud" being up on the network (it just uses the latest versions). Multiple versions could exist in parallel with different names in the cache.
This may all sound more complex then it is, but from a users point of view it will be very simple to use.
Plan B, is to have a task to emit a binary serialized blob to distribute by hand (kind of like Edsons ant task can do).
If anyone has experience with jboss cache/tree cache, let me know, I would appreciate any advice and assistance.