During its Technology and Manufacturing Day Intel has shared a slide of a server-processor with 28 cores. The die-shot as such must be the Skylake-SP series of products in the Xeon Platinum range.

Yes, Platinum. Each core would get 1024KB of L2 cache. The Xeon SKUs always have been segmented into a numeric schema, like the E5-2640 v5. Starting with the 8000 series the 22 to 28 core models will be the flagship products, these will be the Xeon Platinum series.  The 14 to 22 core parts 5000 and 6000 series will be the gold models.  The 4000 series on their end will get 10 cores, will be the Silver series.
 

The new processors will be based on a new socket (Yes intel LOVES new sockets) called LGA 3647. Earlier on a user on the Anandtech forums already posted the new lineup and specs on these processors, though that remains unconfirmed information. It is unclear yet when Intel will announce the new Xeon processors. 

Intel Shows 28-core processor die-shot