As was announced on the OpenESB site and on Mark White's blog, Milestone 2 of the upcoming GlassFish ESB v2.1 release is now available.
This milestone includes many bug fixes compared with the previous milestone. Also, AIX is now a supported platform. Next to the "full installer" that includes GlassFish v2.1 and NetBeans 6.5, there's now also a component bundle installer that only installs the runtime and design time components on top of an existing installation of GlassFish and NetBeans.
With Milestone 2, GlassFish ESB v2.1 is nearing its destination: there's only one more milestone planned before the release. Milestone 2, like any other OpenESB distribution and component, can be downloaded from the OpenESB downloads page.