Skylake-S introduces a number of changes compared to Haswell that makes it fairly attractive as a platform including the move to DDR4 RAM. It also uses less power, runs cooler, and has some very significant performance improvements in some applications.
Z170 vs Z97: What is the Difference?
With the release of the first Skylake-S CPUs, Intel has also launched the new Z170 chipset. Unlike previous launches where Intel releases all the new chipsets and CPUs at the same time, this time only the top chipset and unlocked (K-series) CPUs will be available at launch.