So, I think that if you only want to go gaming, the 7700k is better today.
Amd "may" improve their CPU or motherboards may improve but that is not a guarantee.
In terms of encoding, streaming and everything else Ryzen does look very good and it performs better than Intel in performance per dollar.
I personally will wait a bit longer and make my decision for next upgrade later.
In terms of core count vs core speeds (and also instructions per core efficiency), people were talking about going higher than 4 cores in 2006. We are at 2016, and still no high core count Games are out.
Why? Because its damn hard to code a game for many cores. This is because even if you manage to perfectly (and this is almost impossible) split the work load between cores in a particular game, you still have to:
A) Make sure Windows understands that correctly and uses the resources correctly. (So Microsoft has to do its job right as well, and that does not depend on you)
B) Make sure that antivirus, firewall, etc (additional load from other sources) does not mess up the core load balance. (Again, outside of your control).
C) Make sure that the shortest command sent to a core is done fast enough that it wont block other cores from going on with their next command (this is a problem even in GPU-CPU communication, HDD/SSD-CPU, RAM-CPU, Kernel-CPU, USB Inputs-CPU. Basically what most people call battlenecks)
D) Manage each different hardware set up so it works balanced with the CPU and the load it has.
E) Make sure it will still work well on lower core count CPUs (other way you wont sell your game to a lot of potential customers).
On the flipside, faster cores means.... its just faster. Thats it. No additional coding, no additional balance or hardware.... you see why this is the easier thing for game developers.
The good news (or bad) is that the core speed is limited by the hardware itself. So eventually there will be no way but to increase core counts and balance loads. Now, when will that happen, is anyone's guess.
Thats my take on it.
I will personally wait a bit and most likely go for Ryzen. Either 1 or dual socket Ryzen (1700). no rush here :D.