I wouldn't find generic maps very useful. I can make maps with traps and hazardous terrain on them just fine.
What I do find difficult is mixing the traps/hazards with monsters in a way that is interesting. If these maps came with suggestions for monster types, that might be very useful. For example, "Place some artillery-role monsters at location C, and players might charge them, triggering the pit trap," or, "A large brute monster could block the corridor between 1 and 2; if there's a troublesome leader or artillery monster behind him in room 2, it could force the PCs to crawl through the side tunnel to reach monster in room 2." That level of interaction -- a creative and interesting encounter framework rather than just a map -- would be great.
You could even suggest specific monsters at certain levels (for example, present a level 1, level 4, and level 8 encounter). For major bonus points, include monster stat blocks, so that I can just print it and go. You could even leave this step up to the community! ("I used the 'Forest Ruins' map last night with these monsters in these positions and it worked great...")
-- 77IM