That processors still very good though, I have it
If your only doing standard things, you shouldn't need dual core yet.
But, if you think you'll want it in the future, its best to have a motherboard that'll support dual core straight out of the box as well as standard single core 939.
They are going to be dropping in prices soon though. Check the thread out that should be near the top of the Hardware and Software section.
X2's are going to drop 50% in price. You might want to wait until then. Not long to go really.