It was my understanding that the codec has been ratified and we should be seeing hardware encorders at this point. Yet all these new 4K cameras being released at still h.264.
Does the GH4 even have an HDMI 2.0 connection on it?
What I've read so far, h.265 needs some serious computing power to be fast enough for live recording. I believe it will first be seen as an end delivery format for streaming 4K content before we see it as a recording solution on cameras.
But I confess not having followed it's development very closely.