It went from 512mb ram for minimum requirements to 1gb ram and 1gb ram for optimal requirements to a 2gb ram.
Projected Minimal PC System Requirements
* Dual Core CPU
* 1 GB RAM
* GPU with Shader Model 3 and 256 MB RAM
* Windows XP or Windows Vista
* Dual-layer compatible DVD drive, 10 GB free space on the hard drive
Projected Optimal PC System Requirements
* Quad Core CPU
* 2 GB RAM
* Fast GPU (8800GT level) with Shader Model 3 and 512 or more MB RAM
* Windows XP or Windows Vista