that requires providers to encode the transport stream in H265 which is at this time or any near future not likely. streaming h264 to a box that supports h265 wont speed up anything.
the codec promises some awesome stuff, you are correct in that, and some early HEVC/H265 rips are already out for the few to test. :)
but before every box and your mothers laptop support H265 I do not think we will see it replace H264.