The guide is still a work in progress, however it contains enough information to get you going. You'll find the guide and the API docs on every Griffon distribution too.
On to the features, the first one allows you to abort the shutdown sequence if needed, via a new type of listener (ShutdownHandler) that can be registered with the application. The second feature gives you more information about the application, this time it's the current running mode (joins the existing application metadata and environment features).
Another interesting tidbit about what happened at Gr8conf, the Hackergarten held its third meeting (and the first one outside of Basel) with close to 40 people this time! We broke into several teams, contributions were made to Groovy, Grails, Griffon and Gradle. Regarding Griffon, the team managed to write 3 GDSL files that provide code suggestions for Swing nodes on views, threading and MVC members (don't forget to check the Griffon Guide to learn more about those methods!). Big thanks to Kasper Fock and David Askirk for initiating the GDSL work and making most of the contribution.
Many thanks to the Gr8conf organizers, their sponsors, speakers, attendees and Copenhagen, it was a blast! Let's do it again next year! 
Keep on Groovying!
