This would presumably let x86 windows games run on ARM hardware.
This is almost certainly meant for the next Valve VR headset, but ARM has so much better power efficiency than x86 that a future ARM based Deck would be a huge improvement to battery life.
Also see this tweet:
VR games that have already secretly pushed Android ARM builds onto the Steam Store are ran via Waydroid (androidARM to LinuxARM)
VR games that do not have an ARM build on Steam (windows x86) are being translated/emulated via ProtonARM and FEX
Edit: here’s gamingonlinux coverage of this info, includes some more information
Rosetta and proton are two completely different layers.
Game porting toolkit is indeed also based on wine, but that’s only the conversion of directX to ogpl or vulkan (using metalVK in Apple’s case)
Rosetta is a completely separate harware accelerated (as in, the chips have dedicated hardware for this) translation layer for x86 to ARM
Given the lengths they had to go through to get even this custom APU, I can only imaging the difficulty in procuring a first-gen ARM offering from AMD.
I swear, this is just the “VR is really here, and it’ll replace conventional gaming!” Debate all over again. I’d be surprised if it happens in the next two years. After that? Maybe, if x86 doesn’t catch up more than it already has (which I fully expect it to do).