Eurogamer recently got an early scoop on the preliminary work being done on Episode 3. Yeah, if you don't like some spoilers, then don't look at this.
Perhaps tellingly though, in a separate discussion about moving the player towards the team's "ultimate goal" over the course of the episodic trilogy, Speyrer mentioned that a lot of work had gone into "creating a natural progress of topography and climate". Our emphasis.But seriously, given the events that unfolded in Episode 1, and the very telling excerpts in the "Raising the Bar" book (which I just finished reading and it was awesome), none of this should come as any surprise to Half-Life fans.