Intel is rushing in its 8th generation Core mainstream-desktop (MSDT) processor lineup, codenamed "Coffee Lake," later within Q3-2017. The first four of these will be six-core SKUs, which while built in the "LGA1151" package, the same ones as the 7th generation "Kaby Lake" and 6th generation "Skylake," will not be compatible with motherboards based on the older 100-series and 200-series chipsets, for reasons unknown. Upcoming motherboards based on the 300-series chipset, could support not just 8th generation "Coffee Lake" processors, but also older LGA1151 processors. The chipset lineup consists of the Z370 Express, which features support for CPU overclocking and 2-way multi-GPU; and the mid-range B360 Express chipset, which could launch either in late-2017 or early-2018, alongside the first Core i3 "Coffee Lake" chips. The first wave of motherboards to go with "Coffee Lake" processors will hence be Z370-based. VideoCardz compiled a partial, but growing list of motherboards which could make up the first wave.
ASUS

ROG MAXIMUS X HERO
ROG MAXIMUS X HERO (WI-FI AC)
ROG MAXIMUS X APEX
ROG MAXIMUS X CODE
ROG MAXIMUS X FORMULA
ROG STRIX Z370-G GAMING
ROG STRIX Z370-G GAMING (WI-FI AC)
ROG STRIX Z370-I GAMING
ROG STRIX Z370-H GAMING
ROG STRIX Z370-F GAMING
ROG STRIX Z370-E GAMING
PRIME Z370-P
PRIME Z370-A
TUF Z370-PLUS GAMING
TUF Z370-PRO GAMING

ASRock

ASRock Z370 Fatal1ty Professional Gaming i7
ASRock Z370 Fatal1ty Gaming K6
ASRock Z370 Extreme4
ASRock Z370 Killer SLI/ac
ASRock Z370 Pro4
ASRock Z370M-ITX/ac
ASRock Z370M Pro4

Others

MSI Z370 GODLIKE GAMING
ECS Z370 LIGHTSABER

The first Core i7 and Core i5 "Coffee Lake" desktop processors could launch alongside compatible motherboards based on the Intel Z370 chipset, some time in October, 2017.