Coinciding with the release of today's Crimson Edition driver and Radeon Settings, AMD has ended driver development for non-GCN Radeon video cards. Series' affected include the Radeon HD 8000 (HD 8400 and below), Radeon HD 7000 (HD 7600 and below), Radeon HD 6000, and Radeon HD 5000.
AMD says the decision allows them to "dedicate valuable engineering resources to developing new features and enhancements for graphics products based on the GCN Architecture."
15.7.1 will mark the final WHQL certified driver for video cards in these series'. However, AMD isn't leaving you out in the cold: a Crimson Edition beta driver and Radeon Settings are supported. It's strongly recommended you make use of the Crimson Edition driver partly because it includes a lot of love for DirectX 9 games, which you're likely to be playing if you run one of these older cards.
Grab the beta driver at the source.