Compared to the Haswell-EX series of CPUs which offered upto 18-cores and 36-threads , this is definitely a huge in core count increase .Moving to their new 14-nm processing node,Intel with Broadwell-E can now fit more transistors in smaller space making the core count possible.
Talking about the socket where it will fit it,these new chips are backward compatible with the previous generation Intel E7 v3 platform obviously with a BIOS update similarly as Intel did to Broadwell-E desktop CPUs fit into X99 motherboards which already existed.
Not likely to the Intel’s X5 Xeon series and nor like the Intel’s X99 Broadwell-E series CPUs,these new chips will only have limited 32 PCIe 3.0 lanes each although which can be expanded as these chips are designed for multi-socket configurations like from quad socket and so on.
With third party node controllers these chips could be used in upto around 32 socket configuration with Intel supporting natively upto 8 socket configuration .
Now calculate these eight socket configuration socket using 22-core Xeon E7-8890 v4 could push up the core count to ….total 176 cores!!
Although these chips are not made for consumer grade uses and will be used in high performance servers and workstations.