I'm currently considering my next upgrade too. I did wonder about the "7700K" and the new Z270 chipset but information is minimal, especially regards the latter! As others have said, the tiny incremental changes we see between generations suggest that an upgrade
now if you need it would be as worth while as any time.
Personally, I currently run a 2500k @ 4.6ghz and a pair of GTX 680's on a fully water cooled system. I've had the upgrade itch for a while now, and have a full build - with water cooling elements - all spec'd up. All I'm waiting on are GTX 1080's to come down in price, actually be available rather than "Pre-Order" and have a viable Water Block options - did you know that the current EK GPU Blocks (which look lovely) do NOT support the new High Bandwidth bridge? The things simply don't fit!
While the 1070 appears to offer great value, and the RX 480 even more so, for me it's more about "Performance Threshold" than "FPS per £" both the 1070 and RX 480 have the latter, but fall short of the former for my
personal requirements. Well that and I want the 1080 just cos...
Anyway, personally I'm happy waiting. The big title I was afraid wouldn't run well on my ageing system was Fallout 4, and that's surprised me. I had been set on Skylake + 980Ti's last year, but held off when FO4 performed well with a few graphical tweaks.
In many ways, currently I'm more looking forward to doing the new build, than actually
using the new build, as my current rig is still doing the business.
At the end of the day, only one person can tell you whether to upgrade or wait and that's you. For me, waiting to hear about Pascal, Polaris and Broadwell-E prior to jumping was just common sense and those techs were all imminent and potentially offered more than incremental jumps in performance. Skylake 6700K to Kaby lake 7700K however does not...but I'm always prepared to be surprised!
Scoob.