EDIT: According to Activision these are unofficial and "the official requirements [are] coming soon"
Nvidia's GeForce site has recently released what the hardware requirements are going to be in the upcoming Call of Duty game.
- Operating system
- Windows 7 64-bit / Windows 8 64-bit
- CPU
- Intel Core 2 Duo E8200 2.66 GHZ / AMD Phenom X3 8750 2.4 GHZ or better
- RAM
- 6 GB
- HDD space
- 50 GB
- Graphics card
- Minimum: NVIDIA GeForce GTX 550 Ti / ATI Radeon HD 5870 or better
- Recommended: NVIDIA GeForce GTX 780
- Sound
- DirectX Compatible Sound Card
- DirectX
- DirectX 11
- Internet connection
- Broadband connection and service required for Multiplayer Connectivity. Internet connection required for activation.
Source: http://www.geforce.com/games-applications/pc-games/call-of-duty-ghosts/system-requirements