Like I said, in play of course the PCs are front and center, and stuff that can't possibly affect the PCs is probably not going to get tracked much, unless I'm personally into it. The point is I never want to treat the world like it exists for the PC's benefit. As soon as I can't see the setting as existing independently (even if that's not really true), I lose interest. Plot and character are without meaning if setting is just a backdrop for both, and I try very hard to make the world feel as real as possible.