Jason Dillon just released the next incarnation of the Groovy plugin for Maven [1]. Among the updates and new features you will find

• Moved codebase to the Groovy project
• Runtime support for Groovy 1.5.6 and Groovy 1.6-beta-1
• Support for static imports when generating stubs
• Re-implemented the stub generator to allow more code to be shared between runtime implementations
• Re-implemented archetypes using the latest maven-archetype-plugin (aka archetype-ng)

You can read more about how to setup the plugin and other features at the release announcement [2].