There is a short list of parties who will be unauthorized to access your frame buffer: You. There is a long list of parties who are authorized to access your frame buffer, and that list includes Microsoft, Apple, AMD, Intel, ATI, NVidia, Sony Pictures, Paramount, HBO, CBS, Macrovision, and all other content owners and enablers that want your machine to themselves whenever you’re watching, listening to, reading, or shooting monsters with their products.
The immediate impact of this would be vendor-locking when it came to, say, playing back a movie. Without the proper software, for instance from the vendor in question, a Blu-ray disc might be totally worthless. Potential circumvention aside, one must wonder what AMDs intentions are. Obviously they aren't looking out for the customers at this point, because the backlash DRM is facing only grows each year. Criticisms aside, it seems they are pandering to content providers – the last thing a company trying to compete with Intel and Nvidia should be worried about.
Think twice, AMD. It isn't Sony who brings in your bread and butter.