[jrockway]

I am willing to bet a lot of money on the opposite side. My guess is that all existing x86/x86_64 code will continue to work just as well as it did before.

My guess is that CPU microcode designed to detect that h264 decoding being offloaded to the GPU was from a Usenet post instead of from Hollywood would be difficult, if not impossible, to implement. (My point: the CPU doesn't even see bits from the video to decode anymore. So it probably can't fuck them up, even if it wanted to, which it doesn't.)