We'll have to wait on pricing for Steam Frame, but I don't expect them to match Meta's subsidies, so I'm betting on this being more expensive than Quest. I also think that streaming from a gaming PC will remain more of a niche thing despite Valve's focus on it here, and people will find a lot of use for the x86/Windows emulation feature to play games from their Steam library directly on the headset.
If they get everything working well I'm guessing we could see an ARM powered Steam Deck in the future.
Despite the fact it uses a Qualcomm chip, I'm curious on whether it retains the ability to load alternative OS's like other Steam hardware.
I think it should: we have Linux support/custom operating systems on Snapdragon 8 Gen 2 devices right now today, and the 8 Gen 3 has upstream support already AFAIK