I'm by no means an extreme overclocker, but I comfortably ran a Sempron 2800 at 2320 MHz (290 MHz x 8) on an Abit NF7-V (nForce3 250 board). I was very impressed with the performance of this inexpensive chip and, if paried with an nForce3 or nForce4 chipset, will perform great for you. It will absolutely best your overclocked Athlon XP 2500.
I do want to ask, do you already have the chip or is it going to be free to you? If not, there are some other inexpensive options to consider. You can get a socket 939 Athlon 64 (single core) cheap these days and still use your PC3200 DDR. What do you have already?
-MINOT-