Midnight is a way cool new setting for D20 D&D from Fantasy Flight Games. It came into the shop in the middle of this week, and I got a chance to look through it, and this is not only a great idea, it has been executed extremely well.
Basically, it's set in a world where evil has triumphed and the good gods can't help, and the heroes are sort of the last vestiges of resistance trying to hold onto hope. It's fairly dark, but it's rife with possibilities for taking D&D beyond hack and slash, and the world seems well-realized and (judging from the publishing schedule) well-supported.
Probably the coolest things to me are the new magic system, which allows anyone (not just spellcasters) to learn minor amounts of magic, the redefined character classes and races to fit into the world and specifically the gnomes. In this world, the gnomes live on big barges that roam the waterways, becoming the transporters for this evil empire... but they're secretly the best smugglers and spies in the world thanks to their nomadic existence and relatively free ability to travel.