Snapshot means it's always the latest version. Whenever something is committed to the source repository, our continuous build makes sure everything still works and generates new artefacts. So if you download a snapshot release, that should include all features and fixes available. You can always get the latest snapshot artefacts here:
https://hudson.jboss.org/hudson/job/jBPM5/lastSuccessfulBuild/artifact/target/
Kris