'Coffee Lake' isn't compatible with your current motherboard says ASRock
There have been some Intel 'Coffee Lake' rumors over the last few weeks, including hexa-core chips for notebooks and for desktops, and that the U-series would have quad-core options at 15 Watts. For the desktop chips, there had been speculation that they would still run on the same Socket 1151 and 200-series motherboards as Kaby Lake.
ASRock's twitter account (@ASRockInfo) has inadvertently confirmed that new motherboards are required for Coffee Lake. In reply to a customers question "will the Z270 Supercarrier get support for the upcoming [Intel] Coffee Lake CPU's," ASRock replied, "No, Coffee Lake CPU is not compatibilble [sic] with 200 series motherboards."
Unless someone at ASRock has had a huge misunderstanding over which CPUs will run on their motherboards, they have just confirmed for us that it will be an expensive upgrade for anyone with a current Skylake or Kaby Lake compatible Socket 1151 motherboard. Those wanting to upgrade will have to shell out for a new motherboard, new Windows license (if their current license is an OEM one), as well as the new CPU that they had their eye one.