Microsoft released SharePoint Framework as a “Release Candidate 0” drop, meaning the solution is complete and undergoing testing at this moment. General Availability should follow shortly.
The new release is available for developers HERE.
Release notes are available HERE.
In the meantime, if you wish to learn more on SharePoint Framework, you may check the webinar by one of our authors, Tomasz, about tools and addons needed to develop there. Watch the recording: