Some people have asked when 3.1 is going to get released. You can keep track of it here: https://github.com/jMonkeyEngine/jmonkeyengine/issues/315
Normen doesn't have much time anymore so I am managing the SDK release process. The plan is to have a "3.1-alpha" release for the SDK which then has the capability to update to newer releases like "3.1-beta", "3.1-rc" and eventually "3.1" which is the official release.
At the same time as the 3.1-alpha release, Maven artifacts will be uploaded and an engine-only distribution package will be available to download for those people wishing to use their own IDEs.