Hikvision first started talking about Power over HD Coax at the beginning of 2016. Dahua started marketing it in the middle of this year.
However, we have confirmed with both companies that Power over HD Coax will not be coming until later in 2017. Sources explain that this will take additional engineering resources / complexity to implement (not impossible but not drop in ready from the chip provider).
It will be interesting to see if, when and how this gets delivered since one of IP's clearest advantages today is the simplicity of one cable / one switch / no external power supply of PoE.