Honestly, if you're an OC'er who is dedicated enough to have LN2 setups, odds are you have access to ES samples anyway.
Both Intel and AMD have been known (and I can attest to this personally, having headed up Bit-tech's modding section for years) to be VERY supportive of the TRUE OC and modding groups. I never had a problem getting very high-quality parts for those crowds if I could show a sufficient history of performance.
I know ES chips seem like a very 'cloaked in secrecy' thing that only a handful of sites and people get their hands on - in truth, that's quite accurate. But there are a lot more of them made than actually find their way into the hands of press et al, and the companies hold those for "marketing" budgets that would make sensible use out of them while still respecting the rules of what an ES chip is about (no resale, return to manufacturer at end of life, etc).
One thing is for sure - In four years of running Bit's modding/OC stuff, I have NEVER gone to Intel OR AMD with a proposal and left empty handed. Both companies are extremely friendly to the professional modders and OCers if they're approached with a good project and with the backing of a reputable source.
Odds are the board is as cherry-picked as the chip, but so what? I have two GB ES boards and one Asus that are now collecting dust - but when I was running Bit's watercooling testbench, this was a "must have" and the companies wanted to make sure that I could test the cooling the best without being limited by hardware.
I just wanted to put that out there - we need to remember that hicookie is a professional OCer who has won quite a few competitions and spends loads on his cooling rigs (or at least Gigabyte does!). It is not unusual for someone who works in that capacity to be provided ES samples, and it shouldn't be looked down on. Your "average end user" would never know how to safely administrate a LN2 cooling setup in the first place, and would likely not have the skill to max out an OC anywhere near what is capable with the hardware they HAVE (I know for a fact that I can't, and I'm certainly not new to the process)...so this is nothing to do with "wow that chip is so awesome," and everything to do with "under the absolute right conditions - perfect chip, perfect board, perfect ram, perfect cooling...we can get to HERE..."
In THAT light, that's pretty f***ing impressive.