Just spotted this on the grapevine:
It's the most detailed interview I've seen thus far, and the decision map is discussed, as are future plans for spin-offs, sequels etc. Well worth a read. Here are a couple of key quotes that I hadn't seen before:
"Distilling the essence of the key things in the storytelling that have generated the great reception was the first job for us. Now that we believe we’ve done that as best we can, with a huge amount of help from the press and player feedback, we are working on building on these strengths and eliminating anything we see as a flaw. We’re now applying all of that to a new project, and that’s very exciting."
"now applying to a new project" - that's the first I've read that suggests they're actually moving ahead with (and not just talking about) a new project based on this foundation.
On the issue of Let's Plays and whether they affect sales: "I do believe that there are people watching the choices that others are making and wanting to get hands on to make their own choices and see a different story play out, and that this has had a positive effect on sales."