Local game, sure. Retailer, sometimes.
I never did get my FLGS to stock freakin' Backdrops, which I hear sold great. Then the manager complains about dipping d20 sales. Gah.
Everything I've seen about Nyambe makes me think it'll be a terrific read, which always translates into a valuable game supplement in one way or another. How much of Oriental Adventures have people been using in their otherwise-European campaigns? Nyambe will work just the same way, I imagine. Think Iberia, think Persian bazaar (with exotic wares), hell, think Gladiator.
It's a good thing there'll be a lot of retailers at GenCon. It's easy to doubt books out of a catalog. Harder to turn down Mr. Dolunt's informed writing and full-color artwork.
word,
Will Hindmarch
(I seldom run big packaged adventures, but Nyambe and Necropolis do seem a good fit, don't they?)
Edit: forgot to sign my name, for cryin' out loud.