DDR5 is coming very soon, with memory standards firm JEDEC saying it will finalize the specs for DDR5 technology in 2018. DDR5 will succeed the current-gen DDR4 RAM, with twice the speed, more power efficiency, and double the density of DDR4.
DDR5 arriving with double the density will be great for the market, as it will offer larger DDR5 kits (say 32GB-128GB) compared to what we have now. DDR5 will most likely drop into servers and high-end workstation/gaming PCs at first, and then it'll filter down to other devices, and even appear in low-power form for laptops and mobile devices.