Intel will do something that it never did before. It will release two processor generations at once in the desktop space. The Haswell refresh Core i7 4790, Core i5 4690, Core i5 4690K, Core i5 4690 and Core i5 4590 will be replaced by both Tick and Tock parts.
The fastest of the lot, the one that replaces Core i5 4790K Haswell refresh, is a Broadwell generation processor. The next generation Skylake-S processor will end up slower than Broadwell one and if nothing major changes both will end up branded as Core i7 processors. Broadwell seems to be the fastest Core i5 as well, followed by Skylake-S cores. Traditional desktop LGA Broadwell has TDP up to 65W, something that Intel can change in a heartbeat and supports DDR3 or DDR3L 1.5V memory.
Enthusiast Skylake-S has a TDP of 95W indicating that it might end up faster and it supports both DDR4 with 1.2V and DDR3L with 1.35V voltage. Broadwell 14nm is coming with Iris Pro graphics while the Skylake-S 14nm also promises a new graphics microarchitecture.
Of course, Core i7 5820K, Core i7 5930K and Core i7 5960X remain the fastest of the intel offer until they get replaced by a next generation Core i7 codenamed Broadwell-E. Haswell refresh and Core i7 4790K will get a replacement in Q2 2015 when Intel simultaneously launches faster Broadwell and slower Skylake-S LGA cores.