FreeMarker/Velocity/WebWork Plugin

I want to create a plugin for IDEA:

http://wiki.opensymphony.com/display/WW/IDEA+Plugin

The hardest parts appear to be:

• Code completion

• Refactoring support

• Find usages

While it would be nice to make this work for all template languages, if someone (like the Velocity/FreeMarker team) wanted to team up and help do this for just a single template language, that would be fine too.

The goal is to allow users to be able to write their templates and do $[Ctrl]-[Space] and see a list of valid entries.

Is anyone interested in helping out? Or can people at least provide some hints on getting this going?