Guys, I'd be hesitant about upgrading any hardware until 1.01 patch comes out. If it is true about CoD running 32-bit/single-core then there is clearly major optimisation work to come (
link to simhq thread re 32-bit/single-core).
Might be better to wait and see what the first patch addresses before upgrading and then you will be in a better position to determine exactly what your own hardware bottlenecks are.