Each Hypertransport bus in each core runs at 1000MHz :-D
That means the two cores can talk to each other at 1000MHz which is really fast :-D
I think the 2000MHz FSB is marketing talk, while each core does have a 1000MHz FSB by itself that does not really equal a 2000MHz FSB.
Update: WRONG I dunno what I was thinking. It really is a 2000MHz FSB.
Please do correct me if I'm wrong.
The sad part is your RAM doesn't run that fast.
A Dual Channel config would be better for anything you want to do so grab a dual channel memory kit and use a dual channel capable chipset which would be any decent non-crippled chipset these days.
The nForce4 and VIA K8T8xx are both very good. I recommend the nVidia in most cases, the VIA being the 2nd choice.