Best theory ever:

I just found this, I didn’t write this. The guy doesn’t even do that much research before writing away.
“The G-Man’s employers are Valve Software
The G-Man is the personification of Marc Laidlaw’s attempts to keep the story linear. As such, it is the G-Man that is to blame for the weird coincidences that keep Freeman on his feet. As the series progressed, G-Man gained more of a personality and characterization, leading to his replacement by the Fourth Wall breaking Vortigaunts in Episode 1.
The series will end with G-Man taking Gordon to meet his employers, upon which the player will view a video recorded by the staff at Valve, thanking them for playing and doing some minor story exposition. The game will then close. When the player attempts to reopen them, the “New Game” button has been replaced with “New Game Plus”, which features dialogue from Gordon.”
Here’s the full page:

Every time I hear “dialogue from Gordon”, I cringe. That is SUCH a bad idea, I don’t get why people keep bringing it up.

So what is the purpose of this thread, exactly?