I will be speaking Wednesday at the GR8Conf the Groovy and Grails conference.
I put effort into the CRaSH plugin for Grails that was started 2 years ago by Stephan: I updated it to the last version and also I improved the integration with dedicated Grails commands.
The plugin is not yet deployed into the Grails plugin repository, however you can build it and deploy it locally with "grails maven-install".
If you are a Grails users, it would be awesome to test it and provide feedback.
cheers
Julien