Apparently it is a move to ready the world for Zen which will also integrate the DRAM modules. It is sad that AMD is so far behind Intel that it has to release products for its rivals before it can ship its own.
The new AMD Radeon R7 DDR4 memory modules have dual-channel 8 GB memory kits rated to run at 2133MHz or 2400MHz with CL15 timings, which are pretty decent for your casual DDR4 DIMM kits meant for Z170 systems.
It is not clear if the modules will feature Intel's XMP (extreme memory profiles) technology. If they don't, the DDR4 DIMMs would be of little help to new Z170 chipset owners since they won't be able to enable XMP for extra performance.
The Skylake platform and the Haswell-E, and the vast majority of future DDR4 supporting platforms will run DDR4 DIMMs.
Intel has announced a vast portfolio of Skylake-based CPUs, ranging from the desktop, locked "T" models to the low-power "Y" and "H" ones, all working with DDR4.
AMD 's new DDR4 Radeon memory modules will have cross-chipset compatibility between Skylake users and future "Bristol Ridge" and "Summit Ridge" processors with "Excavator" and "Zen" cores that will also support DDR4 using the upcoming AM4 form factor. Existing AMD APUs support only DDR3 memory modules.
The Radeon R7 DDR4 memory modules are currently available in select stores in Germany and are not featured on AMD's official website.