The official driver seems to be about to release 2.8 while Morphia integration was said to be on the roadmap for 3.0, but I couldn't find any updates on that or any code (in a branch on GitHub).
Is this still on the roadmap and if so, are there any details available on it?

Integration of morphia in java driver, the announcement that Morphia will be integrated into the official Java driver has been more than a year ago: http://blog.mongodb.org/post/5217011262/improving-scalable-java-application-development-with-mon

The last commit has been 2 months ago: http://code.google.com/p/morphia/source/list

The last (snapshot) release has been 6 months ago: http://code.google.com/p/morphia/downloads/list