Looking to help out? Here are some areas where we're looking for assistance:

• Tell us (via pxe-user) what you like about PXE and how to make it even better. Or, tell us what you don't like about PXE and how to make it better. (Ideally, send us a patch!)
• Implement an extension to BPEL, e.g., an expression langauge module for a business rules engine or a custom activity.
• Implement a protocol adapter for the service framework to support your favorite protocol (e.g., JMS) or interconnection with your favorite ESB. If you're willing to work under the MIT License and sign up to support your work, we'll consider adding it to the PXE distribution.
• Build a sample application with PXE and write a tutorial about how you did it. We'll either publish your tutorial here or link to a posting elsewhere.
• Create some interesting integrations with third-party products and projects. J2EE application servers not already supported, SOAP stacks, and non-relational (i.e., native XML) persistence are good candidates. As above, we would be happy to publish (and attribute) a tutorial as part of the documentation for PXE or link to an external site.
• Add WSDL/BPEL pairs to our smoke test suite. (Ideally, check them with the compiler first and correct any obvious errors; however, tests to provoke specific errors are also of interest.) Be sure to tell us what tool (if any) you used to generate the BPEL and what changes (if any) you had to make for the compiler to accept it, as we expect to supply porting scripts (or a -b0rked flag for the compiler) for fixing bad BPEL generated by some commonly used design tools.
• Add tests to the spexerciser for areas of the BPEL specification not already covered.
• Find and report bugs, especially obscure ones.
• Help with internationalization or provide translations of message bundles.
• Draw a (cool) logo for PXE.

And, if you want to get directly involved with the development and evolution of PXE, sign up for the pxe-dev and join the conversation.