This is great news. Before 2-3 years i7-3770K and i7-4790K were better options than i7-3820 and i7-4820K.
I would not go on 4 cores i7 any more. But mainstream processor with 6 core will have higher frequency than 3.8GHz and probably Turbo  4.0-4.2GHz, maybe even more.
That would be nice processor, special for Mini ITX boards. Than price of 8 cores will drop for 200-250$ probably.
 

I like the name :)

Let's not forget that the VP of intel said that CPUs will get a bit slower, but way more power efficient. I estimated from when the statement was given it would occur as early as ice lake, but maybe coffee lake since this is the first I've heard of it. Can't wait for cappuccino lake.

Just imaged a lake made from coffee.

I guess I really don't understand the NEED for more cores in a "mainstream" PC...  Right now and for the foreseeable future they really do no good.  All this will do is lets people stroke their cyber ego at a lower price point lol.  I see this turning into a cores war similar to the old GHz war - because the average mainstream PC user doesn't know that 4 higher clocked cores would trump a lower clocked 6 core system most of the time.  Not only that but you have the sales folks at worst buy and the other stores feeding incorrect info often just to sell something so add that to it.  
 
To me this is akin to so many people I have tried to recommend a PC or laptop to with a SSD and they get talked into one with a platter drive by a salesman or themselves.  Oh you only recommended me the 256GB one and I got the one that has 1TB for less money!  Why wouldn't I want more for less??!?  Also looking at it's reminiscent of the newer Android phones with the "octacore"+ processors and the OMG I NEED MOAR COREZ.  But looking at NON BENCHMARK numbers my old Nex6 with quad cores at much higher clock speed still keeps up in side by side speed tests.

I think if Intel launch CPU with 6 core in mainstream they become more popular than 6 core extreme for people with single graphic card.
Special now with Gen3 Chipset. But I think 8 core will replace 6 cores in Extreme class. 8 cores is really not necessary for gaming.
But 6 cores will work better for 2 years than 4 core and no one buy processor for 12 months only.
Very small number of people will buy slower CPU with 40 PCI-E lanes, or 48 if rumors are true with same number of cores as Coffee Lake with 500MHz higher frequency. Example i7-3770K was much better to me than i7-3820 with 40 PCI-E lanes. 
Xtreme Processors become excellent on 4GHz+ and overclocked Cache Frequency. 
I would like to replace i7-5820K with i7-6800K but that's not my priority and I need money for graphic card,
but i7-6800K is little better single threaded performance and X99 platform become even
better with him and negative side of X99 platform compare to Z170 are much lower with Broadwell-EX.
i7-6850K 40 PCI-E lanes is more expensive. not worth for single GPU and everything could work nice even with 28, even two GPU.
I searched him if show up for some cheaper price as I bought i7-5820K but nothing for now and I need all money for GTX1080.

Hmm so Kaby Lake in late '16-early '17, Coffee Lake late '17-early '18...
 
First one that can OC well, I will buy. I want 5.3GHz (minimum) 4C 24/7 on water.