Google today announced a new so called Rich Media Tool. As far as I understand it, this tool is the replacement for the current Structured Data Test Tool.
Currently the tool only supports the following schema classes. That’s maybe the reason why it does not show anything on my websites (as I do not use one them).
Hopefully the Google team will integrate more Schema-Classes in the near future. What I like so far that it shows a more accurate preview of a snippet, like this one which is a German WordPress JobPosting portal:
