I got tired of seeing the Grails icon whenever I was working with Griffon, so fashioned my own Griffon icon and then recreated the whole set of modules from scratch, with a completely fresh check out from hg. I.e., the first time I did everything on a hunch: I had the hunch that getting from Grails support to Griffon support would be a matter of branding. This time, I knew that was true, so went about it all a bit more carefully and have come up with a more reliable result. Still a few problems to fix though. Also, the Griffon support should, ideally, work in the same IDE as where Grails is found (though that's not a hard requirement, I think). So, enough things to do.
Meantime, here are the screenshots. You start with the project template:
...which creates your application and opens it inside the IDE. This time, the logical view is much better than before, with more nodes displayed:
There are many menu items on the project node, such as 'Run' and 'Compile' and so on, which all work. Similarly, on the folder-level, you can choose menu items which pop up GUIs for creating the Griffon artifacts, like controller, views, etc, via the actual Griffon scripts in the official Griffon distro that do the work under the hood. I'm hoping to be able to make some kind of distribution available in the Plugin Portal soon.