Although I too am looking forward to seeing the 8700K's gaming performance, I'd be surprised if it keeps up with the 7700K in most games due to the 8700K's default lower base clock of 3.7 GHz or so...; if it OC's on all 6 cores to at least 4.2 GHz, then it might surpass the 7700K at stock, but, not sure what clock speeds the 8700K can sustain... No one knows outside of an Intel lab....
One things for certain...the 7700K is damn fast NOW at $300, and that won't change no matter how 8700K performs at $385+.....
In any event, we won't know for another month or so, the official 8th gen launch only began with a paper launch of laptop parts...; the 8700K will come later 'in the fall', which is probably October over September...