Good article I found on Burt's blog today.. I have found this to be so true, everyone can gain from Groovy. It's too powerful to ignore the ability to add all of the meta programming abilities, and so easily have code write code or pull code out of the DB and run it, or even give a good to a simple email template system using SimpleTemplateEngine(). Add to it the relatively simple process to introduce into the Java build process of most systems, why not, what do you have to lose?
At KPI we started with Groovy by just using it to write unit tests, using almost completely looking like Java. As you get into it, and try new things, you'll be hooked in no time :)