This it the official message from our programmers:
Will Dof support multi core cpu's
Right now DoF supports dual core CPU`S. In fact to get a decent performance out of DoF you will need a dual core CPU - which majority of PC users already have.
We didn`t include support for Quad CPUs yet - and I`m not sure if we will, as Due seems to be good enougth to run all the aspects of the game.