InfoQ has a short synopsis of the event proposal that was released to add pub-sub style semantics to the SCA assembly model. The genesis of this lies in some ESB related work I had helped lead at Oracle back in the days when we first started to develop the SCA specifications - it took a long time to socialize this to the working group, but I'm very happy to see that that work has borne fruit. This fills an important gap in the specifications - previously, the wire driven semantics forced components to "externalize" pub-sub interactions in a way that was divorced from the SCA semantics - and is broadly applicable to many problem domains including Complex Event Processing, Queue/Pub-Sub style integration, and ESB scenarios.
I remain somewhat distressed over the way the channel abstraction has played out - the original idea divorced much of this from the assembly view and made it an aspect of system configuration. I think the current approach artificially mixes orthogonal aspects of the problem space. Having said that, this is a milestone for the specification and completes the basic assembly model nicely.
By the way, nice write up Boris!