If you watched the most recent Playing Dead episode, there's a lot of subtext to read into. You can get a lot of information from the video, which is here ( http://www.youtube.com/watch?v=QngiVxj3RZU ) if you haven't seen it. This - video and the analysis here - will contain spoilers, so this is your final warning.
Walking Dead will have one ending. This has been set in stone from the start and it was stated in the video that it is not going to changed. So, while Jurassic Park had two (or three endings, if you count dying at the very end as another), it sounds like Walking Dead will have one set, unavoidable ending.
Gary Whitta states that he pushed for the most messed up and foul scenarios he could imagine, and caused everyone - including Dave Fennoy - to recoil. While I didn't think so at first, I now believe that the man over the radio is a lecherous rapist. Let's all have a tub full of bleach for when we're done with episode 4 ready.
In the panel, the designers give a more clear definition of what "tailored gameplay" means. You have a game that fits with you, but you aren't "making clothes yourself", in a way that allows your choices to dictate everything. The game is "handed to you" to put in the final bit of input. This means that your choices will never matter in any way deeper than how it resonates with your own morality. But it also goes against another quote from the panel about the big mysterious choice that's been long rumored in Episode 4. Episode 4's choice is described as "so crazily consequential and branching" by Gary Whitta at the 30 minute mark.
What does that mean about choice? That this is the biggest break in the storyline and can change the story in a distinct way? Are all choices still small offshoots that quickly close back to the same inescapable plotline in the way that choices do in Mass Effect and Heavy Rain?
Is there anything else you picked up from the panel?