We already talked a little about the fact that Intel would/might be releasing another chipset called Z390 later this year. That is next to Coffee lake 6-core processors on what is to be the Z370 platform. A Z390 motherboard now has surfaced in the SiSoft Sandra database.

Intel has an 8-core 14nm Coffee Lake processor in the works. The information surfaced from an XTU errata log is showing change-log entry that reads out as "[CFL] Added support for 8,2 core,", see below. CFL obviously is short for Coffee Lake.  

 
It would be an interesting move from Intel, as typically they design one desktop processor and base all models off from that one proc. To create an additional processor holding 8-cores is very unusual. If correct, this would be an 8-core/16-threaded part in the mainstream segment, and that would mean serious competition for AMD Ryzen 7.

The new info is derived from videocardz, who spotted the unit in the Sisoft database. it is listed with a 6-core proc (we assume the procs will be backward compatible. The entry comes from SMC (Super Micro).  While originally intended for release late 2017, I do expect a launch Q1/Q2 2018 realistically with how incredibly low stock is for Coffee lake processors.

Intel Z390 motherboard spotted in SiSoft Database