Looking back, and keep in mind I'm watching John Carpenter's sci-fi movie on my Hauppauge TV-tuner-capture-card while I write this -- the industry seems to lurch forward like "The Thing" going through its shape changes. Different parts of the technology are never in perfect sync.
True, there are industry "task-forces" and ad-hoc inter-corporate panels devoted to setting new standards, and if you watch the industry news (there used to be a publication called PC Week, but I don't take it any more) -- you can keep abreast of these efforts.
For my part, I would say you would prefer over-clocking if you want to open up bottlenecks farther down the storage pyramid -- especially now with the still-prevalent memory and FSB standards of DDR400 and 800 Mhz. Since P4 processors are still "locked", they only way you can go beyond FSB 800 is to over-clock, and that may be better than buying a faster processor and using it with DDR400 memory and DDR400 settings. That's why I bought DDR500 RAMs and started looking around for a CPU that would over-clock and stay cool.
Now, with DDR2 and 1066 FSB, the "standard" is catching up again, and Intel is now touting its 3.8E (or is it EE?) P4 CPU on the LGA775 socket, tested with an i925 chipset. And the round begins again.
On the other hand, whatever rationalizations you can dream up, this is just another addiction. But we don't have 12-step programs here -- those are for over-clockers who are also credit-card spend-thrifts. I may SAY I have this rationalization that I made above, but some people just like to blow money on parts and then try and push them to the limit. For instance, phase-change or refrigerative cooling -- geez -- the AseTek Vapo-Chill kit costs some $800 last time I checked.
And no -- you can't just buy a mediocre system and expect stunning results from over-clocking. You trim your budget here and there -- for instance, processor cost --and use the savings to spend on other parts that complement the plan.
Anybody ready to buy themselves a PCI-X mobo, and PCI-X x16 graphics card, yet?