Here's something that could be exciting but also could be a whole lot of nothing. So keep expectations firmly in check, but work submitted for Linux kernel 6.6 show something interesting from Valve. Potentially a Steam Deck refresh or their new VR headset perhaps?
Valve has openly stated that they only work on things that interest them, which is why unless there is some interesting new technology to play with (like they played with VR for Alyx), there will be no HL3.
I can totally see them chasing the shiny and dropping VR to focus on Steamdeck as the new Shiny, and then dropping Steamdeck to focus on whatever the new technological shiny is after that.