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
the lighter workloads isn’t like stardew valley levels workloads, it would be like watching a video level loads. Just being arm doesn’t outright make it that battery friendly, its like the non application use(e.g sleep, super basic app) where the battery level is better. The qualcomm laptop reviews kind of show that platform when its battery life is mildly better than last gen amd/intel chips and worse under gaming. Qualcomm rushed the release because they new they needed to release before AMD’s Strix Point and Intels Lunar Lake to make it look like they were more efficient. (X elite was on TSMC N4, Meteor lake was on N5/N6, Phoenix and Strix were on N4X, but they knew AMD would have the highest NPU performance had it released first.
the BIGGEST flaw that the arm based designs have that isn’t tegra is that their graphics drivers are inferior to both Nvidia and AMD, and graphics drivers play a huge role in whether something works correctly or not.