Actually no. The speed you get is actually per core. So if you have a 3GHz Quad Core CPU its 4 times 3 GHz. The CPUs actually work so that if you are not using all cores, they give more power to the active core.That and what's with the "per core" thing?
Isn't it common knowledge that the CPU frequency power is split between all cores? A quad core CPU with 3Ghz will have somewhere around 750Mhz per core.
Leaving that aside... it seems like the minimum system requirements are decent for the age we are living in and for the graphics we've seen so far.