Recently we posted a slide demonstrating the Z370 Platform transition chipset for Coffee Lake. Interestingly enough that slide  revealed a Z390 chipset which was listed on there. As it turns out, Intel is to release yet another chipset this year, to support 8-core processors. 

That fact is also indicative that the Z370 chipset isn't enough, and not capable of supporting the unannounced 8-core part. It's messy with Intel chipsets alright. The news was spotted at the NotebookReview who posted a bit from eurocom stating the obvious. The Eurocom employee claims that Z390 is supported by eight core and sixteen threads processors and would be released in the second half of 2018.

 
That statement completely lines up with the slide we posted earlier.  So that means a B360, Z370 and Z390 chipset. Eurocom has indicated to simply skip Z370 and go straight for Z390, which indicates that Z390 will be backwards compatible with Coffee Lake 6-core processors. But that last bit remains speculation of course. Btw we have a hunch the 8-core part would/could be based on 10nm Ice Lake.
 

Mystery solved: Z390 Chipset Will Support Intel 8-Core Processors