The official UK Playstation site have put up a QA with Greg Donavan, associate producer on Red Faction 2. The article covers GeoMod, gameplay, weapons, environments and more, well worth a quick read. Here's a taster:
Can we expect to see different environments now that the game's set on Earth?
Well, you're not going to have the underground mine environments we had in the first one. In this one, we have exterior and interior environments, everything you'd expect. It's reality based; although it's in the future, nothing great has changed on Earth. Also, we've got some new weather effects.