Half-Life 2 chatting continues here. The game's been unlocked on Steam and showing up in stores, and so far the word is extremely positive. When discussing game events and story elements don't forget to use the SPOILER TAG.
In case you're having problems starting the game, check this post from Valve's Erik Johnson. There's a brief Valve Q&A about the game on the G4techTV site. Update: Here are some notes kindly provided by the Valve guys in the comments here: