I do hope they will release drivers for the Steam Machine, otherwise the openness isn’t very useful. Or at least make it possible for others to make drivers by publishing specifications.
Edit, reply to bjord as I am rate limited: HDMI CEC, the chipset, GPU drivers, controller receiver etc.
Edit, reply to robhlt: Thanks! Hope we can get that ported to Windows
For HDMI CEC they've already published their user-space daemon: https://gitlab.steamos.cloud/holo/linux-cec
drivers for what else, exactly? valve is already regularly upstreaming work in major open source linux drivers (and has been for a long time)
for example: https://www.phoronix.com/news/Valve-Old-AMD-Linux-Love-Song
They did take almost a year for Windows drivers for the Steam Deck OLED: https://steamdeckhq.com/news/windows-is-now-supported-on-ole...