Infinity Ward has released the system requirements for Call of Duty: Ghosts on PC.
They are, in a nutshell, about what you'd expect, though there's been a smidge of upset about the 6GB of RAM in some corners. Have a look for yourself:
OS: 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
Memory: 6 GB RAM
Hard Disk Space: 40 GB
Video: NVIDIA® GeForce® GTS 450 / ATI® Radeon? HD 5870 or better
Sound: DirectX compatible sound card
DirectX®: DirectX® 11
Internet: Broadband Internet connection for Steam and Online Multiplayer.