Intel is being super vague about when we should see CNL. They have indicated that they'll announce CNL by year's end, but have said 1H 2018 volume ramp. We could very well not see systems until mid-2018 on this schedule.
That sucks really, really bad. Let me explain.
If they release Cannonlake in mid-2018, there's zero chance we'll see Icelake before mid-2019.
Now that assumes they are still on the 12 months cycle. There's evidence we're past that.
June 2013: Haswell
Jul 2014: Haswell Refresh
August 2015: Skylake
Jan 2017: Kabylake
November 2017?: Coffeelake
Summer 2018: Cannonlake
Hmm. Yea we're not on the 12 month cycle. Based on that pattern,
Fall 2019: Icelake
Holiday 2021: Tigerlake
Spring 2022: 7nm
We are talking 3 year delay for their 10nm process. Basically, their claims of "3.5 year lead" doesn't exist even if you took their(likely marketing) claims at face value.
Also for Cannonlake ULT 2+2 in mid 2018, they should cancel it. There is no realistic chance against a better clocking 14nm+ with four cores. It's way too late.
Proper yield learning likely requires it to be field tested. The best way is to send it to HVM. If they cancel Cannonlake, then Icelake has to bear that burden. That's why when people claim they should "skip" a process, they have zero clue what they are talking about. If you are having a problem on a simpler process, you'll have worse times on a more advanced one.