William Ronald said:
I think that as FR never lasped into no-support and Eberron is fully supported, that they have not developed the degree of fanbase divergence seen in Greyhawk. (Occassionally, I will see a complaint about the maps between 2nd and 3rd edition, but that is about as far as the divergence between FR fans goes.)
You'd be surprised. The Forgotten Realms schismed quite a lot during the Avatar Crisis, when half the pantheon was killed off. There are still feverish debates about whether Bhaal is better than Cyric. There also seems to be a lot of bitterness in some quarters over regions that have been developed that the original FR set promised would be left to the DMs. Some of the new setting elements, like the Shadow Weave, have their furious detractors. One of the biggest bogeymen is the 3rd edition cosmology, which retconned the entire multiverse it was set in. There are many other issues as well - people who still think Kara-Tur, Maztica, and Zakhara should never have been made part of the world, for example, while others would like to see those regions dealt with again.
Greyhawk schismed most significantly after the Greyhawk Wars, and although there are concerns about some of the things that Carl Sargent, Roger E. Moore, and Sean K. Reynolds introduced to the campaign (and Jim Ward before that), I think any further schisms are fairly minor, and really not a bigger deal than the complaints about things that people other than Keith Baker have introduced to Eberron. The 1998 Greyhawk line went a long ways to bringing the Flanaess back into balance, and I think most fans who continue to buy new material accept the way things are going. Those diehards who refuse to acknowledge anything post-Gygax generally don't buy new D&D books anyway, so they're really not an issue.
Certainly, nothing that's happened to Greyhawk is a bigger deal than the things that have happened to the Great Wheel over the years. I think
Fiendish Codex I struck a good balance between honoring the new and the old, and a similar balance can and has been struck in Greyhawk in the Living Greyhawk Journals, Paizohawk, and the like.
In short, there's no need to please all aspects of Greyhawk fandom, just the segment of it that's still interested in buying new RPG books along with - perhaps more importantly -
non-Greyhawk fandom that might be casually interested in the setting.
I think Greyhawk is the setting that fits most naturally with the core rules, not despite its legacy elements but
because of them. Though many longtime fans of the setting would disagree with that, I think a book could be written that would show that Greyhawk can embrace the new without sacrificing its own flavor.
Whether or not the speculation in this thread has any validity, I think Greyhawk badly needs a new hardcover. The Living Greyhawk Gazetteer is out of print, and had terrible production values compared to what the other settings later got. Something with beautiful, atmospheric illustrations would go a long way toward selling the setting and showing it off as the distinctive thing it can be and is. An introduction discussing the campaign's many possible themes and what makes Greyhawk different would help, too. The Greyhawk Wars are in the past, and most of the nations need to move on, mentioning those events no more than other important historical touchstones, concentrating on the culture and feel of each nation. Finally, a bunch of quick-reference appendices (lists of rulers, gods by cultural origin, a timeline, maps of the Flanaess at different points in history, a list of what features and major events are associated with what nation, a list of what monsters frequent which regions, a list of prestige classes found in various core books that fit with specific setting elements (or how they could be made to fit), an INDEX and so on) would do wonders to making the book more usable.
The Living Greyhawk Gazetteer was a great book, but needed better presentation and focus to really sell it. I hope the setting gets that.