Mouseferatu said:Speaking only for myself, I think it's a great idea.
I love the "limited release" model for campaign settings. (It's worked very well for White Wolf, for instance.) It's enough to give the basics of the setting, without hyper-detailing every little corner of the world--that, at least to me, is the perfect mix.
That said, there's no doubt whatsoever in my mind that the settings will see expansion, in DDI articles. And I'm also willing to bet that if the three books exceed sales expectations, WotC would probably at least consider expanding the lines down the road. But again, those are just guesses.
#1 place you'll see expansion material: DDI. Gives more reason for people to buy into that (for better or worse).
#2 place you'll see it: Adventures. The expedition series did at least moderately well (I'd say probably a bit better than that even), so that might be a good way for them to focus in on a certain key area, toss out some adventure ideas, and expand on this place, that place, this NPC, or that deity. Or whatever.