Previously AMD released drivers for their CPU's way back when. I don't remember if they helped much, but they could attempt that again (though I don't know if they can fix the scheduler issue with drivers). They could try and trick the OS into thinking there are 4 cores instead or something.
When AMD released the Dual-Core Optimizer/patch for X2's, it did help performance quite a bit, or did it? I can't remember.
That was also on XP and things are different with XP to Vista/7 and soon to be 8.