Radeon drivers are out now for new RX 470 and RX 460 owners. Whether you have the card or not though, there are some other relevant bits in store.
Apart from the new card support, you get a CrossFire profile for Codemasters' F1 2016 (nearly two weeks ahead of launch), plus a variety of issue fixes (most notably for the subpar CrossFire performance in DOTA 2 and low framerate or stutter in Wolfenstein: The Old Blood on the RX 480).
For the full notes and download, hit the source. Alternately, just update through Radeon Settings.