Q: Is this going to remain Forgotten Realms only, or are other settings/IPs to be considered in the future??
A: We intend to open up additional settings and IP as time goes on. However, for the time being, we will remain focused on the Forgotten Realms.
So it's definitely possible, even likely (especially considering they brought Ravenloft into the fold), that Greyhawk will be an option someday. I have to reiterate that I have no idea when that will happen, or even if it ever will, but I am basing all this on the (admittedly speculative) idea that it will. Eventually. I'm guessing within two years, but it could be next week for all I know (in which case, boy am I behind schedule!).
With all that said, here are the sortakinda product announcements, dependent entirely on whether or not WotC ever adds Greyhawk to the list of settings in the DMs Guild. Even if I just end up writing them for my own game, they'll get written.
Players Guide to Greyhawk. A collection of new class options, backgrounds, spells, magic items, etc. etc. etc. Basically fleshing out all the options the game currently has, with Greyhawk-specific material. This is more than half written right now, for my home game, and some of it has been published here on the blog.
a very detailed, small-scale map of the whole region, and in the "mostly already written" category. I'll proceed to be much more systematic in filling in the pieces. Will have information on history, politics, and economics; notable NPCs; settlements and natural features; and of course plenty of adventure hooks. There will be stuff in there that sets up the Greyhawk Wars and beyond, but a DM wouldn't need to go in that direction by any stretch of the imagination. Would be written for 5E, because that's what the DMs Guild wants.
Temple of Elemental Evil 5th Edition Conversion and Campaign Expansion. This one is also mostly written, again for my own use. Not only would it include 5E stats for all the NPCs and monsters, but a revised (fixed) map and a brand-new dungeon level four, for DMs who want to end the adventure more in line with the original intention, including a link to the Elder Elemental God (and thus tie-ins to Vault of the Drow). Will also include brand-new material detailing other old Temple outposts (including the Watchtower at the border of the Suss and Gnarley forests), Sobanwych, which Temple agents have thoroughly infiltrated, and those two "danger, evil!" symbols on the High Road in the original maps:
Verbobonc. A complete sourcebook detailing this critical town and surrounding Viscounty commanding the Velverdyva River, set in CY 576. Will detail the city itself, with a large map, plus lots of separate adventure hooks too, of course. Obviously this city could loom large in a ToEE campaign, and so fits in nicely with the above. This is something I haven't started writing at all yet.
the rivalry between Chicago and Milwaukee), standing at the western end of the Nyr Dyv, as of CY 576. Will include a full-sized map and sourcebook detailing each quarter of the city, notable NPCs, and the like. This is something I'll have to write from scratch. I've got a map roughed out, but that's about it.
I might also do a couple of stand-alone adventures in the region, just to flesh out some of the potentialities.
But of course this is a weird situation, as I'm going ahead with the work of writing even before I know for sure that there will be able to ever sell the damn things. But the way I figure it, this is as much an excuse to sit down and get the work done for my own campaign; a 5E sandbox stretching from the Wild Coast to the Nyr Dyv, the Mistmarsh to the Kron Hills.
Consider it being written "on spec" (and I have one or two projects that are on deadline and must be finished first), and setting me up to be ready out of the gate if and when WotC ever opens up the DMs Guild to Greyhawk products. Look for announcements about Kickstarters right after that happens (for art and editing, as always), but I've always had products written and in-hand before I went that route in the past, and I will want to do the same here.
* This blog isn't called Greyhawk Grognard for nothing. :-)