AMD at CES shed some light on its 2018 roadmap.
AMD 12nm Ryzen launches in April 2018 and AMD says that first 12nm Zen+ processors will have higher clocks and support Precision Boost 2 technology. AMD confirmed that chipset X470, will also launch in April 2018. According to AMD.
AMD 2nd Gen Ryzen Threadripper in 2H 2018
AMD also confirms that desktop Ryzen Threadripper series will be released in the second half of 2018, same with 2nd Gen Ryzen PRO series.