Greg, My idea when starting this thread is more along the lines that Sandip just described. Never thought of having Java replacing elisp as *the* Emacs extension language. I'm thinking more about aligning JDE with other Java IDEs in terms of support for Java plug-ins. Yes we can always rewrite most of those plug-ins (although GUI-intensive extensions like UML support would be a stretch) in elisp; or we can have customized elisp glue around those Java libraries, that will have to be coded from scratch for each one. It is a fact that there is already a lot of interesting packages in Java out there that would be nice extensions to JDE. Isn't it better to re-use them than to have to re-write them from scratch? But having a well defined Java plug-in architecture will definetely save designers time in the long run, and hopefuly would be an incentive for more designers to come up with extensions for this great development environment.
Regards, Nascif