Then isn't it nice that WotC is leading with something unusual like Eberron (while supporting something traditional like FR), rather than putting out Greyhawk 2: Electric Booglaoo? Or even, "We've got the basics covered; you d20 folk, go nuts."
Well, technically, TSR already did Greyhawk 2: Electric Boogaloo several times over:
Forgotten Realms
Mystara
Birthright
Dragonlance
They also did some fresher stuff too:
Spelljammer
Planescape
Dark Sun
Some culture-specific fantasy:
Al Qadim
Kara Tur
Maztica
The Horde
European historical stuff:
Celts
Vikings
Mighty Fortress
They're maintaining Forgotten Realms, so that's their Greyhawk 2: Electric Boogaloo setting, but it's long in the tooth, and I suppose it can't really be dropped because it still spins money. So Eberron is a compromise; an attempt to have another Forgotten Realms, but different enough not to be Greyhawk 2 and compete directly with FR...but not to have too much of a twist either (like Dark Sun, Spelljammer and Planescape had) because it had to support novels. So Eberron is perhaps a result of Forgotten Realms not being retired, and for criteria which it can support with regards to selling novels (must have enough Greyhawkesque generic fantasy tropes not to be alien) and D&D product (e.g. all inclusiveness of monsters and races).
When viewed in this light, it's more about compromise than leading the market - TSR's more off-the-wall settings were leading. Eberron is aimed directly at the markets, and at least partially defined by that. So in a way, it's a world of compromise. Forgotten Realms saw compromise from the early days too (thinking mainly of stuff like importing the "British Dragonlance" setting as Moonshae and the slapping on of all the culture-specific settings), but perhaps in a less calculating way, and not at a foundation level...but then, WOTC is better at making money than TSR was, so they're just doing what good corporations do.
Still can't help thinking that the criteria which were being looked for were a result of thinking inside the box....that maybe some sort of Setting Construction Kit or something (not suggesting this idea is any good, just pointing that other possibilities are there) would have been a better path (given that that's something DMs love, so helping them with it seems a potential source of income - TSR dipped their toes in that area a couple of times, but something much grander might take off more), if not for the fact that that doesn't generate novels and computer games. It'll be interesting to see whether Eberron supports all of D&D, novels and computer games - or only one or two of them - successfully. Dragonlance supports only the former, whereas FR seems to manage all three.