Like Jedi said, Kaby lake is coming out soon. While it will no doubt bring some sort of platform improvements, the IPC (instructions per clock) performance is identical to current Skylake processors.
What's more interesting than that, and coming soon (whatever that means) is AMD's ZEN which will supposedly have the same IPC as skylake and kabylake and will probably be sold for a lower price, with lower priced motherboards, if AMD holds true to its style.
Traditionally for some time now, AMD has sold its motherboard chipsets and processors at a lower price than Intel. So, theoretically, if a 6700K/7700K is $360, a 4 core ZEN CPU will be maybe 250 or something.
I don't know what to tell you, it all depends on what you want and when you want it. There is certainly nothing wrong with going with Skylake right now. All signs point to you not being able to squeeze higher IPC than that out of anything for the forseeable future.
Sorry but nobody can give you a really precise answer right now. We are at a time where the new stuff is coming soon and we have a pretty good idea of what the performance of the new stuff will be so you kind of have to make the decision yourself based on that information.
I see nothing wrong with buying a skylake system right now.
