IGN has posted another blog from Ken McCulloch, Director of Content. In it he summarizes how the plot will be unfolded to the gamer. Here is a quote from the blog:
"This goes to show that there's more to storytelling than just relating 'what happens.' Storytelling is not simply sitting down and working out a progression of events. This is doubly true for video game storytelling, where you have to mete out content in the pace and rhythm of the gameplay to avoid alienating the player who might just want, heaven forbid, to play his new game."