The DTK, which must be returned to Apple at the end of the
program, consists of a Mac mini with Apple’s A12Z Bionic SoC
inside and desktop specs, including 16GB of memory, a 512GB SSD,
and a variety of Mac I/O ports. Developers can apply to the
program at developer.apple.com, and the total cost of the program
$500 rental — great deal, really.
Interesting but not surprising that Apple (a) never once mentions “ARM” by name, and (b) hasn’t revealed the name of their custom Mac chips yet. They’re just saying “Apple Silicon” as a placeholder for a name to be revealed when they begin unveiling actual consumer hardware.