I have a feeling that, regarding bringing old settings back, there is already so much fluff out there that people have already purchased that WotC doesn't think they can sell it again. D&D is a product built on many older-edition customers who already have all the fluff they could ever want, and there are probably Wikis for all the people who missed out on those old books and boxed sets.
This is true, but you have to remember that some of that old gaming material is REALLY hard to find in good condition. And when you do find it, it usually costs a lot more than your average gamer is willing to pay.
Yes, there is e-bay, but it's a risk. You might win something great or it might be in terrible condition. And the best material from the best sellers isn't cheap.
That is why I liked the fact WotC redid Dark Sun, even though I still have my revised and expanded 2e Dark Sun boxed set (not to mention various other DS boxed sets and accessories).
And while I'm not sure if I like what WotC did to the Forgotten Realms, I consider the new FRCG to be a great book worth hanging on to. (I didn't keep the player's book, however.) And I'm looking forward to Neverwinter.
And if WotC redid Greyhawk, I'd burn a hole in my pocket buying it and any other books they create for the setting. A revised Greyhawk would make me seriously consider getting a DDI subscription, which is what WotC wants!
And if that Greyhawk setting went back to its roots similar to what WotC did for Dark Sun, I'd become a D&D 4e/WotC fan once again. And if the second sourcebook was a revised version of the City of Greyhawk, I'd be thrilled. The best third product would be a Greyhawk themed Monster Vault!
Forget about making a new Greyhawk adventure. WotC has already redone Tome of Horrors. That's all a Greyhawk campaign needs!
The only other revised setting that would make me more thrilled would be Mystara!
It has been more than a decade since Mystara has been in print. I know tons of Mystara fans who would KILL for a 4e revision! I think the best selling Mystara product would be a Monster Vault that updates all the classic Mystaran monsters.
I would SOOOOO buy that!!
Cheers!
Knightfall