Somewhere here and several times through '07 and before March, '08, I'd posted some guesses about the chip-making process, their quality-control, binning and testing. And I ventured to speculate about the economic imperatives for producing a product-differentiated line of processors. I posed an implicit question: "How do they choose the retail-box maximum voltage?" and supplied a speculative conclusion that failure rates over a range of voltages, and failure rates over extended time, were exponential probability distributions. I said that the accounting-side or marketing-side of the house would influence a choice to pick those specs as an assurance of near-0% probability of RMA warranty returns within the 3-year warranty period.
A March, 2008 Anandtech article pretty much validates my guesswork and deductions.
That being said, their choice to spec a CPU as "1,333 Mhz FSB" would probably follow the same logic. They're capturing certainties about existing technology, and as motherboard makers, together with their competitors ASUS, MSI etc. and the chipset designers, they've simply spec'd to a standard which is, again, based on finding a line that defines a "near-0% probability."
They don't HAVE to say "1,333 FSB" or "1,066 FSB." So there would also be a range of operability around those choices as well.
I won't go into detail about the "serious stuff" I'm doing with a mildly over-clocked Q6600 -- only to say that the data files are stored on another stock-clocked networked system with a RAID5 array and two levels of firewalls and other security features. But I have broken -- slightly -- the rule that I would insist be followed if you were doing something like real-time patient-monitoring in a hospital, or controlling the Diablo Canyon or San Onofre nuclear power plants.
Personally, I think if you're OC'ing a processor in a family of processors for which the flagship model is spec'd to run at your own choice of an over-clock setting, your worries are speculative and probably exaggerated. Your worries about losing the support of the manufacturer or losing some court-case because something went wrong -- are worries about dead certainty. Besides, most of us aren't using ECC memory, and there's the occasional cosmic ray that might change a bit-setting.
I actually think I "know" Person1 with his EEE degree. He thinks his mother is trying to poison him; he bought his house for $85,000, and has now run up his mortgage debt by refinancing it to a 2006 $350,000 market-value, which is now, in turn, in the toilet. He whines that Vietnamese immigrants in the electronics industry have underpriced his labor and taken away his livelihood. And several of his friends have cut him off, because "That boy has problems! He may even be . . . . dangerous!!"
Nope. I'll say this, though. My favorite Anthony Hopkins movie is "The World's Fastest Indian."
[Now, to push that CPU_FSB up another 5 Mhz . . . . . . . Hey! get your hands off the shutdown switch to my reactor! I'M running things here!! . . . . ]