Here are some highlights I've checked out during the evaluation process:
- Grails combines the best open source technologies into one easy to use framework (Spring IoC, Hibernate, Spring MVC, Spring WebFlow)
- Additional integrations are as easy as one-line plugin installation (Jabber integration, JMS integration, additional view capabilities, JavaMelody monitoring - just to name a few)
- ActiveRecord pattern as well as dynamic finders rock!
Stay tuned for some working examples. I'll post them during the weekend.