well, a lot of us are overclocking to get a good processor without paying too much for it. As such, we want value. Throwing away a perfectly good CPU (and mobo, since a socket 754 CPU won't take you to 2.6GHz without some pretty extreme cooling) is pretty foolish, especially when the CPU/mobo is less than a year old. I find it hard to believe that an A64 at 2.3GHz "sucks the bucket." No, it's not an FX, but it has like 85% of the speed of the FX-55, so i don't see how it's gonna make your software crawl or anything. The only thing an extra 300MHz would buy you is maybe some braggind rights, nothing more. Save your money. Towards the end of next year, you can get a PCIe SLI dual core system, and that will actaully be worth the upgrade.
Honestly, i don't understand some people around here. I hear people talking about upgrading like every few months; what the hell is the point? So you get an extra 10FPS in HL2? Is that worth hundreds of dollars? It would be like buying a new car every year, and throwing away the old one because it's not the newest model anymore. I personally refuse to upgrade until i can at least double my speed. After all, i can still run games on my 700MHz athlon system that is five years old (btw, it ran jedi academy, max payne 2, warcraft 3, neverwinter nights, c&c: generals, and others at decent resolutions), so i don't believe that people really NEED to upgrade any more often than every 18 months/2 years. Granted, i don't recommend waiting 5 years between systems, but i also think your system is good enough that you have no need to upgrade for a while yet, until new technologies emerge that really make for a compelling upgrade.