Hardware makers don't like sync or standards. They like platform lock in and exclusivity to motivate buyers into buying their product over a competitors, or buying both. Honestly, the steam box will end up being an x86 processor of some description with some ddr3 memory and a discrete gpu of some kind, designed to run games well at 1080p, and they will probably use some kind of boot-to-steam system (I mean steam has its own web browser and everything already!) where they replace the usual DE with just big picture Steam.