I can certainly see your point in counting official licenses to third parties. In such case, the count would include not just Dragonlance but Ravenloft and Gamma World (both licenses since reverted). I think a very large number of Greyhawk fans would enthusiastically welcome a license of Greyhawk to a third party publisher if Wotc would not be interested in reviving the setting itself. Of note, such a revival need not necessarily include "12 supplements a year" etc. I think the large majority of Greyhawk fans who would be pleased to see the setting revived would welcome just a "300 page" core setting treatment to start.
The rub with a license, as I understand it, is two fold. First, I am given to understand that Wotc has been approached about a Greyhawk license previosly, most notably by Paizo Publishing, and that no agreement could be reached. Second, the principle reason no agreement could be reached was supposedly Wotc's perception that Greyhawk was too close in flavor or core audience to the Forgotten Realms and that a published Greyhawk setting would thus detract from sales of the Forgotten Realms or, put another way, Wotc had concerns that if both FR and GH were published settings the market for medieval fantasy D&D would be fractured, hurting both properties and the bottom line.
Whether any of the above actually influenced a decision not to have already licensed Greyhawk, I actually believe that as presented in the FRCS and the LGG, FR and GH are too close in feel and potential audience. I think they would fracture the medieval fantasy market and hurt the bottom line. This is where mattcolville's post upthread was right on the money, IMO - "Just being Greyhawk isn't enough, it needs to fill a need that the other settings don't fill." I think this thought should be part of any equation to bring back Greyhawk, whether by Wotc or through a licensee. Greyhawk needs to be clearly distinguishable from the Realms such that overlap in audience appeal is minimized.
While the "high fantasy" vs "low fantasy" differentiation has been offered as a point of distinction, I don't think that would be enough. Of course, the devil is always in the details but it is for this reason that I support restarting Greyhawk in its entirety, keeping material or themes that work for the new design but otherwise charting new territory and in that process making Greyhawk sufficiently distinct from the Forgotten Realms such that the two settings would not be competing for almost the exact same audience. Wotc could certainly undertake such a design and any licensee could be required to present such a design outline as part of the process of having a license approved.
With respect to "core" being considered its own setting, I take your point but I cannot fully agree because a setting is a consistently presented background in which either published adventures or home brewed adventures can be set and by this definition, the "core" presentation is simply not definable as a setting. While an argument could be well constructed that the D&D Gazateer (3.0 Edition) created the necessary "core," I feel this argument fails because almost all of the subsequent Wotc releases make little or no mention or use of the D&D Gazateer in much of any way. The D&D Gazateer has also been allowed to go out of print and was never reissued with the 3.5 Edition. If it was a setting, then, it is now effectively passe.
All this to one side, I am greatly heartened that Greyhawk continues to be mentioned in discussions about settings - and even more heartened that there are discussions about settings! Your raising the possibility of a Greyhawk license as another option is, perhaps most heartening of all. Whether Wotc would chose to redevelop Greyhawk or license the setting to a third party, I think I can speak for any number of Greyhawk fans in urging that the process move forward with all deliberate speed. Or as Larry the Cable Guy would say, "Git 'er done!"
If Expedition to the Ruins of Castle Greyhawk is a step in this direction - GREAT! I do think it will do well. I would not, however, tie too much consideration of the sales of Expedition to the Ruins of Castle Greyhawk to the fate of Greyhawk the setting. The two are markedly distinct. Of course, Greyhawk the setting is now out of print and Expedition to the Ruins of Castle Greyhawk is then to that degree an adventure without a setting. At the same time, Expedition to the Ruins of Castle Greyhawk, as I understand it, is no attempt to reimagine the setting, even in part, to be distinct from the Realms, a consideration I believe in any thought of a revived Greyhawk as noted above. Rather, Expedition to the Ruins of Castle Greyhawk is limited in scope (to the Castle and "Free City") and within that scope will hold to a traditionalist approach to Greyhawk in the sense of using familiar and accepted Greyhawk themes/tropes for which the authors have been noted. While sales of Expedition to the Ruins of Castle Greyhawk should certainly be looked at, I would not see them as either predictive nor as a bell weather. Greyhawk "as is" is, I believe, a nonstarter for the reasons set out above and Expedition to the Ruins of Castle Greyhawk does not set out to address the factors behind that reasoning. The adventure should be taken on its own terms and welcomed as such but it should not be stretched beyond that, IMO.
