Anyone here besides me play through the Half-Life episodes in Developer Commentary mode?
If the designers of Half-Life put half as much thought into their story as they did into the cinematography and gameplay of the series, then there would still be an impressive sci-fi conspiracy mindscrew behind the game's plot. I have no reason to doubt them.
And, let's be honest, there really is not that much that has to be explained. Most of the Half-life universes' "plot" is extrapolation from known data anyway. The only thing left in the game that demands explanation is "Who is the G-Man?"
That's it. That's all the player needs to know. Who or what is the mysterious puppeteer who keeps dropping Gordon into suicidal situations? Once that question is answered, pretty much everything else either solves itself or falls to the wayside.
As to the episode itself... I dunno WHEN they'll release it, but I have no doubt that they will. The thousands of slavering fans and their combined income should be plenty of incentive to put it out sooner or later.
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?
Presumably the Vortigaunts talked about your Half-Life escapades to the combine and to humanity. I suspect that they're the ones who started calling you "The Freeman" (The One Free Man) and popularized you as a messiah figure. The G-Man has portal technology that apparently allows him to manipulate time, so there's the aging paradox solved. The Nihilanth's status is a little hard to guess at, but given how the Vortigaunts seem to think you're their savior, my guess is that it oversaw Xen for the combine in the same way the Breen oversaw Earth ("We are their slaves...").