According to the release notes, the new Radeon Software Crimson ReLive Edition 17.7.1 Beta drivers add support for Radeon RX 460 and RX 470 series crypto-currency mining graphics cards, and add support for Radeon RX 550 and RX 560 series graphics cards.
The list of fixed issues includes a fixed bug which causes crashes in Tekken 7 game on Radeon RX 380 Series graphics cards, a fixed bug which causes crashes in FFXIV and Little Nightmares on Radeon RX 300 Series graphics cards and a fixed issue problem which causes a crash with Adobe Lightroom CC 2015.10.
Since these are Beta drivers, there are still plenty of known issues that should be fixed with the next major update. As always, the Radeon Software Crimson ReLive 17.7.1 Beta drivers support all Radeon series graphics cards since HD 7700/HD 7900 days and are available for Windows 10 and Windows 7 in both 32-bit and 64-bit versions as well as Windows 8.1 in 64-bit version.
You can check out the full release notes and download the latest Radeon Software Crimson ReLive 17.6.2 driver over at AMD's support page.