If people remember back to the early days of Java EE (J2EE), there was a lot of promise, but a lot of frustration. I still have mental scars (and a slight eye twinge) from the countless hours tracking down typos in deployment descriptors. But, we were willing to endure the pain because there was a lot of power in the platform.And as a model, J2EE was solid. Sure, there were squabbles over the value of different parts of the model (e.g. Entity Beans), but the general abstractions and approach were incredibly valuable, as evidenced by its success. JBI is similarly positioned.
However, mainstream adoption requires not just a solid design model . Mainstream demands ease of use, immediate gratification, and passionate community support. This is the fundamental appeal of Ruby/Rails and why J2EE struggled in the beginning. In the beginning of J2EE, it was a week long effort to get an EJB deployed. Meanwhile, Rails has caught on like wild fire because it takes less than 10 minutes to get an entire n-tier application up and running.
In an effort to learn from this, independent of the actual implementation communities (Apache - ServiceMix, Java.Net - OpenESB, etc.), we've created a JBI community site jBIZint, where the various implementation communities can come together to discuss common needs that will improve a user's over all experience. If this sounds like something you would like to be involved in, please join the mailing lists.
As an example, there are two movements afoot that will improve JBI adoption and ease of use. The first is a movement to standardize the diagramming technique for service assemblies, and the communication between them. Much like SCA has done, a standard diagramming technique will allow system designers to communicate effectively, the components, meta-data and communication paths of the services in the system. (Again, please join the discussion on the mailing lists to get more info)
The second movement is to get an "easy-install" package management system in place akin to Debian's apt-get and maven's repositories. (credit Bruce Snyder for the idea). This would make it simple to install components through tooling (e.g. Eclipse, NetBeans, or command-line). The package management system would pull down the component and all of its dependencies (e.g. shared libraries), perhaps even a sample service unit.
Combining standardized diagramming with an easy-to-use package management system should make it even easier to pick up one of the numerous "10-minute" tutorials on JBI, like Chad's XMPP-RSS Demo, and get it up and running in 2 minutes with an understanding of how and what you did. =)