Think I might wait before buying anything (game or RAM) as it may change in the future.
@Jamf - I have currently 3 2Gb modules and a slot free for a forth 2 Gb module.
The game runs like #%&*$# right now but it is far from optimized. At the end of the day if you can run another game that runs the cryengine (sp?) you will probably be able to run SC. So MWO would be a good example (it uses crytek right?)