As hinted at in the Half-Life 2: Episode 2 trailer, Valve is apparently getting ready to kill off one of their main characters in the upcoming episode. According to Valve, the move to episodic content, like a television show, gives people a chance to become fond of characters and, in turn, allows developers to start taking bigger risks in each episode. Of course, with the episode not set to debut until next year, they haven't revealed as to who will die, but it's a safe bet to assume that it won't be Gordon won't get the axe.
Gabe Newell, head of Valve, defended Valve's decision:
"I think we want them to care about these characters and want them to trust that we're doing something smart with these stories. We want them to be genuinely worried about the characters, so you won't think 'Well they won't do something to these characters, because they're too important.' If nothing matters, then nothing you do matters - and you're moving away from being in a world and back to being in a shooting gallery."
Valid point, but don't kill off Alyx. She's the only reason I played Half-Life 2 to the end! We'll just have to see which character will receive a death sentence from the evil overloads at Valve, won't we?