Surprised that they have 4 USB-A and only 1 USB-C. With their power profile, Steam Machine should be powerable by a single USB-C cable on extended power range which should reduce the need for the power supply altogether and greatly simplify mechanical as well as thermal design, although the power electronic design would be more complex as a result.

I would also be expecting Wifi 7 support as well as unified memory considering they ordered custom AMD silicon. Understandable that it is a rather conservative design for their first generation though.