AMD Radeon ReLive
AMD Radeon ReLive is a breakthrough new feature being introduced with these drivers. It lets you record or live-stream your gameplay (or pretty much anything on your screen) at minimal GPU performance cost. NVIDIA has had something like this for a while now, GeForce ShadowPlay, but AMD's implementation claims to have a lower performance impact (down to almost negligible levels) and more features.
ReLive is integrated into Radeon Settings. You enable it by simply clicking on a switch. Pressing Alt+Z (or a custom combination you define) brings up a toolbar that lets you begin recording or streaming to your streaming profile on Twitch, YouTube Gaming, or other similar social networks. You also get a great set of tools for custom overlays, such as your channel branding, system information, web-cam overlay, etc.
Below is a short animation that shows you how to enable ReLive, and how to use it.