I was pouring over my World of Greyhawk boxed set over the weekend and my D&D 3.0 Greyhawk Gazetteer and now look at what Wizards has released for us.
OD&D Supplement I: Greyhawk (0e)
Living Greyhawk Gazetteer (3.0)
While Greyhawk is not the default setting of D&D 5, it does get a lot of nice shout out in the rules.
Plus the Living Greyhawk Gaz is 90% setting material, so it can be used in any version of the game really.
This is great for me because as soon as the kids are done with the A series they are headed to the Free City of Greyhawk.