By that same token one of the main goals with Diablo III is to flesh out Sanctuary, to make it feel more like you're in this living and breathing world.
Bashiok: While the crumbling bridge could be taken quite literally, it was intended to get the idea across that Diablo III will have more interactive and responsive environmental hazards.
Every class in Diablo III is a 'DPS' class, and damage output is vitally important, but no matter your build, you can customize your defensive skills as much as your offensive ones.