In addition, Mafia II PC will support NVIDIA's 3D Vision headset for stereoscopic 3D visuals when the game hits August 24 in North America and August 27 elsewhere.

Thankfully, 2K Games also provided an explanation of what the technology brings:

The integration of PhysX and NVIDIA APEX technology, including the APEX Clothing and Particle modules, enable the city and personalities of Empire Bay to truly come alive on Windows PC. The NVIDIA APEX Clothing module allows for more dynamic movement in clothing, making in-game characters even more realistic and reactive to environmental conditions. With the implementation of NVIDIA APEX Particles, players are engulfed in lifelike explosions that are bigger and brighter, including weapon fragments, in-game debris and destructible environments that are amplified in both quantity and realism through the integration of APEX Particles. For example, a pistol fired into a glass pane will emit hundreds of glass shards; a shotgun blasted through a wooden landing will splinter the wood; and a Tommy Gun will chip into a brick or stone wall to methodically fracture and break it into pieces.