yeah, the winnies are freakin awesome! I have my 3000+ at 2.5GHz right now, rock stable, using stock cooling (albeit with arctic silver 5). At these speeds, I'd say you might see an improvement over your setup.
Still, I'd probably wait another month or 2. I think AMD is releasing their Rev E0 chips in march or april, and they will basically fix all the A64 problems. They have SSE3 support, improved memory controller allowing for 4 full DIMMs to operate in dual channel at DDR400, rather than reverting to DDR333 and 2T with the current winchesters. Oh, and they feature SSDOI (strained silicon directly on insulator) so they might overclock even better, say, to 3GHz or even higher. At that point, it'll really be worth the upgrade.