Update: turns out the PC Gamer report was in error, and the new date is actually November 22 in North America (23 in Australia, 24 in France and Benelux, 25 in Europe).
Batman: Arkham City was delayed on PC last month to November, and now we know the specific launch date: November 18.
Patience will be rewarded with optimized controls, higher-resolution textures, PhysX support, DirectX 11 support, and 3D Vision. Plus, according to NVIDIA's games & technology editor Andrew Burnes, pop-in issues are eliminated.
In the meantime, four new screenshots are here for your perusal.