The new graphics memory databook on the website of SK Hynix confirms the company will have HBM2 memory available in Q1 2017.
The part number is H5VR32ESM4H-H1K, it's 4Hi stack HBM2 with a capacity of 4GB, a frequency of 1.6Gbps per pin and a bandwidth of 204.8GB/s per stack. TechPowerup points out SK Hynix is the principal supplier of HBM to AMD and speculates this announcement paves the way for the arrival of the AMD Vega video cards. By using two HBM2 stacks next to each other, AMD could create Vega cards with 8GB of video memory.
The databook says the HBM2 will ship in Q1 2017 but exact availability details are not shared.