Regarding the discussion of where 4C/8T Zen enthusiast AM4 desktops chips would come from (cut down 8C/16T Zen or 4C/8TZen APU with iGPU disabled ) Ideally there would not be many of these. (re: under ideal circumstances all 8C/16T dies would go to server and be fully utilized and all 4C/8T APU dies would go to BGA mobile and be fully utilized with iGPU).
And if AMD is going to make a desktop 4C/8T with whatever scant amount of harvested 4C/8T I don't think it should be 65W. 65W is just too in between a 35W/45W BGA mobile and a workstation level 95W chip to be meaningful or purposeful IMO. 4C/8T AM4 really needs to be 95W. Same goes for any harvested dual core APU, it should also be 95W.
As far as the OEMs go, I think AMD should point them at BGA for desktop and let AM4 be strictly an enthusiast DIY platform (using the handful of chips AMD has leftover from the Server and mobile efforts).
About the whole Zen lineup: I have the feeling that AMD is trying to go after Intel segments and will offer a comparable or better speced part at every price.
Quad cores with IGP? That's mainstream Skylake equivalent, if they price it right a good GPU and 8 thread might be a decent offer against locked i5, pheraps even the unlocked parts.
Eight cores? That's aiming at enthusiasts and will battle mostly the 6 cores, it's what existed when Zen was planned anyway, so current extreme 8-10 cores might be a little out of reach.
For those we might see some 16 cores released at some point, or higher clocked stock parts like the FX-9000.
They are surely in a much better condition to compete with the planned IPC increase, regardless of frequency, because speed can be adjusted with new process/stepping but microarchitecture is the foundation for a whole generation of products. I'm probably more interested in AMD finally getting good laptops/tablets with Zen and their APUs than high end: 4W TDP sounds low enough to finally catch Core-M and all the mobility crowd.