I have been investigating using Eclipse RCP for a GPL application, similar to what you guys are doing with JMoney.
I read, though, that:
The EPL 1.0 is not compatible with the GPL, and a work created by combining a work licensed under the GPL with a work licensed under the EPL cannot be lawfully distributed.
( http://en.wikipedia.org/wiki/Eclipse_Public_License )
I'm curious how you guys get around that restriction (I'd like to do the same thing)