Will Deus Ex: Invisible War have branching storylines as the original did, with the player's choices affecting certain options later down the line? And, taking that question to its logical conclusion, will there be multiple endings? If so, can you say how many?

Actually, I think the player has a lot more control over the storyline in Invisible War than in the first Deus Ex game. In the new one, you can actually decide which faction(s) to support and which to oppose -- you can even change your mind along the way. In the first game, we made you work with UNATCO early on and then leave them later on. None of that kind of thing in Invisible War -- it's all up to you. As far as endgames go, there will be multiple endgames in Invisible War, you bet.