Let's see:
- I'd use this to get my Campaign Setting published as an official D&D one (I'd have to create most of it first, though ;-))
- There'd be a Dungeons and Dragons Miniatures Set called "Forgotten Folk" with gno less than a dozen gnome or gnome-flavoured figures of all rarities.
- DDM sets would have "figure sets", that can be used to represent different ranks of an organization, or a character on different levels. A common soldier, uncommon sergeant and rare captain, for example, each more elaborate and with better equipment.
- Fantastic Location Deluxe: You'd get a couple of maps and several tiles tailor made for that map. The tiles are to be put on specific locations. This would combine the overal seamless look overal representation of maps with the flexibility of old tiles. For example, there'd be a room that is more or less nondescript on the map, but with tiles it turns into an armory, a torture chamber, prison cells. A cleraing in the woods could be a hut, a druids' circle, a sacred pond. Since the tiles are designed to go there on that very spot, the looks won't be disturbed.
- Races of the Underdark. Not exactly FR, but the name sounds better than just "Races that live underground. It would have Drow, Svirfneblin, Duergar. Maybe something new, too, since that seems to be the way to go with those books. Something attuned to stone and the Underdark's radiation. Faerzress-Infused Stonechildren on Steroids or something. PC race with burrow anyone?
- Deities of Faerûn: The Dark Seldarine. We get so little about non-human deities, so we'd expand on that. This book (not too large), would give detailed descriptions (with updated information) of all drow deities (with all the trimmings), prestige classes for each faith (Arachne, Blade Dancer and Darkmask would get a make-over, and the Masked Trator would make its return, new ones would follow), sample temples and shrines, faith-specific spells and all that.
- Deities of Faerûn books for Elven, Dwarven, Gnome, Halfling, and Monstrous Deities. Same as above.
- Alternately to the Deities of Faerûn, I would make quasi-regional books for the big races (like Serpent Kingdoms was part racial, part regional, for all kinds of snake-creatures), containing descriptions of their greatest realms, information about their deities (including updated information), detailed background, the whole nine yards.