rycanada said:
Is it too late for this thread?
Yes, it is doomed
I also think that, as far as content goes, there can be only one. You can't do a Forgotten Hawk or Grey Realms, where the Circle of Eight marries the Seven Sisters and Kelemvor has dates with Wee Jas.
Right now, we have two settings: One with all the trimmings, very detailed and with lots of background; And the other you can make your own - not a lot of information is available (especially in current books), and what is there is there mainly to serve as inspirations.
So the best of both would probably letting Greyhawk go for good (maybe selling it off so some smaller publisher could do something for its fans - a campaign setting and maybe even some settings) and put FR sample material into the books henceforth.
That would mean that the PHB would still have the races it has now, but the descriptions would be those of the Faerûnan versions (which means, for example, that elves are pale and as tall as humans). There would be a dozen or so FR deities as sample deities, and the Iconic characters could easily be moved into the Realms.
The DMG would have different planes to describe (unless they change back the cosmology), and the MM would no longer list the old subraces like Grey Elf, but the FRCS subraces.
It might also mean that Mordenkainen's Sword, Bigby's Crushing Fist and spells like that would have to be renamed.
Supplements would be more tricky: They'd have to have no more GH stuff, but I guess that's not too hard to do, since there's a lot of overlap. There would probably be two types of supplement, though: FR light supplements and Full-FR supplements. Full-FR would mean that it uses a lot of the concepts that are special to the Realms and only found in the FRCS (and they would require the FRCS): Things like the Weave/Shadow Weave and the organisations and churges found on Faerûn.
Realms-light supplements, on the other hand, would mainly have concepts. They would probably get a short description on how they work in the Realms, but would otherwise be usable in every normal D&D campaign out there.