This quad-core with eight threads is a high-end processor that will bring a few small changes. It will be faster within the same TDP, but Intel is not talking about the actual clocks. The fastest Skylake is the Intel Core i7-6700K and it has a 4.0GHz base clock that reaches 4.2GHz on Turbo.
Kaby Lake Core i7 7x00K series will be slightly faster. Intel is telling its partners that the Kaby Lake-S will have 15 percent more high speed input / output lanes. This is only four additional PCI express lanes and nothing that is going to change the world.