JBI 1.0 has not gained industry acceptance. A few implementations exists (e.g., Sun JCAPS and Apache ServiceMix), but a number of vendors and projects that initially supported JBI have discontinued support for it (e.g., Mule ESB and Tibco ActiveMatrix). The vendors tell me that JBI did not deliver any significant benefits and, in fact, limited their products' capabilities.
The JSR for JBI 2.0 (JSR 312) lists a number of improvements that they (i.e., Sun) intend to make to the specification, but I think it might be too late for JBI. I doubt that the ESB vendor community will pay it much attention. They seem pretty focused on SCA at this point.
This was first published in May 2008