The Skara project (http://openjdk.java.net/projects/skara) is not adding new features to Java. It is focused on improving access to the Java source code of JDK.
To access the source code today, you need to download it from a Mercurial repository and compile it manually. The Skara project's goal is to move the source code to Git because Git is now the most popular source repository, and many programmers use it already. The source code of the examples in this book, as you know, is stored on GitHub too.
The current results of the Skara project you can see in GitHub already (https://github.com/Project-Skara/jdk). Well, it still uses a mirror of the JDK Mercurial repository. But, in the future, it will become more independent.
