Sixteen core parts in this big.LITTLE-like configuration will start at 80W TDP and will range up to 125W TDP (possibly even 150W TDP). Alder Lake-S will support PCI Express 4.0 support and will reportedly use the LGA1700 socket so that means you'll need a new motherboard.
Alder Lake-S is believed to be 12th Gen Core and is rumored to be a 10nm part.
It has also been speculated that Alder Lake S will require a new socket (LGA1700), meaning that the upcoming LGA1200 socket will only be used for Comet Lake S (10th Gen Core) and possibly for Rocket Lake S (11th Gen Core?).Interestingly, not even half a year ago, there was a rumor that 10nm Alder Lake got cancelled in favor of going to 7nm Meteor Lake. Guess we'll find out more later this year.
The 12th Gen core series would be the first Intel series to support PCI-Express 4.0. There is no confirmation on DDR5 support. These series are expected to use a 10nm node, although it was never fully confirmed.