I wouldn't hold my breath if I were you. It's another HL3 in terms of never coming out and the developers are nowhere near as good as Valve was back in the day. All they have is a talking head for a CEO who promises a bunch of crap but then goes back on his promises in a blink of an eye.
People who worked on Stalker are now behind Metro, and both of these franchises are much better then overhyped HL games. Especially Stalker. So who is better developer?
And there's no such thing as HL3, not even on paper. They didn't even finished episode 3! Valve is a joke!
On the other side Stalker 2 was already in the development. Story is completely finished, some character models and animations, concept art, etc.
Now i know almost everything about Stalker history. Also i was involved in some video games projects as a developer. I'm not naive and overhyped about this Stalker 2 announcement.
I'm just sharing information.