I'm one of the votes against. Providing city maps (like the town of Fallcrest that will be mapped in the DMG) is great, as is providing adventures with locations that reference each other (as the new H1-H3 adventures will). They can be dropped into any setting with no or minimal changes. As soon as you provide a map, you're providing a world and all that goes along with it (a metaplot, continuity, and other limitations).
This way, it's possible to run an adventure where I can create adventure sites and cities willy-nilly without a player saying, "oh... actually, I read in a novel that this mountain is under the control of duergar, so there's no way it could be the seat of the giant empire."
I like campaign settings, but for the D&D core "world(s)," the Points of Light design philosophy seems like a great middle ground between too generic and too specific.