snack: They're probably still trying to think up a coherent story line for the Half Life series. They've gotten to the point where they have to start revealing stuff only I get the feeling there was never any grand plan.
I was quite disappointed that they didn't do more to bridge the gap between HL and HL2. Like how does everyone in the world seem to know what you did on Xen? Why aren't they suprised to you? You only took a 1 way trip against impossible odds and have reemerged 10 years later, unaged. The big bad you murdered at the conclusion of HL? Those are our allies now and they love you. Is a 30 second explanation too much to ask?
It's almost like two different universes that share a couple characters. :(
If Hideo Kojima could pull MGS4 where he gave a good response to all those batshit-insane plot threads he created, I have faith that Valve can do the same.