Quad-core Core i7-8650U CPU spotted on GFXBench
The successor to Kaby Lake will likely be just a small performance update ever since Intel announced the end of its "tick tock" development cycle in 2014. We fully expect to see 14 nm CPUs once again for at least one more year until 10 nm chips become widely available.
A performance uptick of 15 percent over the current generation of Kaby Lake processors is likely via further optimizations in the architecture and manufacturing process. Perhaps the biggest change to the next generation could be the addition of quad-core SKUs in the 15 TDP U-class family of processors. Thus far, these ULV processors have been limited to only two full cores. If true, the upcoming Kaby Lake successor could be a huge boon to ultra-thin notebooks especially if Hyper-Threading remains.
GFXBench has since taken down the page on the Core i7-8650U, but the original listing was claiming a base clock rate of 1.9 GHz. This is significantly slower than the current Core i7-7600U and its base clock of 2.8 GHz, but a quad-core configuration for the i7-8650U could potentially make up for the deficit and then some.
As for the integrated GPU on the i7-8650U, GFXBench was listing its name as the HD Graphics 620 which would make it identical to the integrated GPU on current generation U-class Kaby Lake notebooks. It's possible that the graphics boost between the two generations will be so minimal that Intel may not need to introduce a new lineup in the HD Graphics series at all.