I was really excited during the early days of Apollo testing when the Artemis project was announced and wrote several sample applications. It was a way for AIR to communicate with Java through a bridge. This project was eventually abandoned.
With the release of Adobe AIR 1.0, Adam Flater who was the driving force behind Artemis, made the announcement that the project would be reinvented under the new name of Merapi.
I have been a member of this project for a few weeks and have used the 1st set of bits to build a small sample application which uses Java on the back end to take a screen shot which is something that is not native functionality to AIR. To see the work I have done including some screen shots and sample Flex and Java code please read the full post at EverythingFlex.com.
Adam has also put together a nice "Hello World" screen cast that I recommend checking out.
The new Merapi bridge is still in private beta but will be public soon. For more information on this exciting project, please check out http://www.merapiproject.com.