AMD halts supporting graphics cards (drivers wise) that are not based on their Graphics Core Next-architecture. That means that multiple graphics cards in the Radeon HD 5000, 6000 and a couple of 7000 series now have been tagged with legacy status. 

Realistically this means graphics cards based on VLIW-architecture, Radeon series HD 5000 and 6000 with type numbers HD 7600- and HD 8400-or lower will drop from driver support. AMD also halts support for APUs based on VLIW, the GPUs in Llano-, Trinity- and the Richland-series.

The legacy status means there no longer will be anymore new drivers. According to AMD this choice clears up valuable engineering resources for the driver development team for newer GPUs and APUs based on GCN-architecture.

Please be aware that owners of these older cards and APUs still can make use of the bèta AMD Radeon Software Crimson Edition-driver released today. However A certified WHQL-driver will not be an option and thus that makes the Catalyst-version 15.7.1 WHQL the final certified driver. AMD launched the GCN-architecture in 2011.