X2 3800+ is $169, thats true. But like I said, the $189 Conroe 2.13Ghz is better than the X2 4800+, so the performance of the X2 3800+ won't be anywhere even close to even the weakest Conroe processor.
And like was already said in the RHT thread, its not going to happen anytime soon. Its a waste of time anyway, Dual-Core supporting games will already support two cores, so making them into one will most likely have a negative impact in Dual-Core supporting games.