Phoronix article: https://www.phoronix.com/news/Steam-Machines-Frame-2026
Also listed here: https://store.steampowered.com/sale/hardware
Valve has already sent support for the new Steam Controller upstream: https://www.phoronix.com/news/New-Steam-Controller-SDL
I forgot where but some time in the last 3 hours I read that the goal for steamOS is to be supported on all PCs, though it’s an ongoing effort.