There is no such thing as an "existing userbase". It's a myth. PC users are not (even marginally) homogeneous. About two years ago I bought an entry level POS Dell laptop. Even it has a Dual Core processor.
C'mon, you knew damned well what I meant by 'existing userbase': the multitude of PC owners who haven't yet upgraded to a multi-core CPU system. I don't know who you think is going to be playing a very complex game, using advanced rendering techniques for special effects, and advanced AI, who doesn't at the very least have a computer better than an Inspiron 6400.
I don't remember reading that's what MGE was aiming for, then again I did only scan this thread.