Intel's future 12th Generation Alder Lake-S CPU is purportedly pictured in a recent article by Videocardz, showcasing a new larger form factor designed to fit into the future LGA 1700 socket. Intel reportedly will use the LGA 1700 socket for two generations of desktop CPUs after Alder Lake-S.
Alder Lake-S will be Intel's successor to the 11th-gen Rocket Lake processors that come out next year. Alder-Lake will feature a hybrid architecture involving high-performance Golden Cove CPU cores paired with low-power Gracemount cores for increasing power efficiency. It will be on Intel's latest 10nm SuperFIN process and marks the first major architectural change since Skylake debuted in 2016.
The socket dimensions for LGA 1700 will be 37.5mm x 45mm, which is about 7.5mm taller than Intel's current LGA 1200 socket. Presumably, the bigger size is to make way for larger core counts than Rocket Lake. For instance, we've already seen hints of a 16-core 32-thread Alder Lake CPU that might be on the way.
Videocardz says DDR5 support should be coming to Alder Lake as well. This is not confirmed, but DDR5 is ready for adoption, and SK Hynix has begun production on DDR5 RAM modules already. So it is possible.
Among many other announcements (full breakdown here), Intel announced at its Architecture Day 2020 that the company would release its Alder Lake-S processors for the desktop PC in 2021. That means they'll be a fast follower to the 14nm Rocket Lake processors that land in Q1, 2020.