Beer News posted the keg ring for Boulevard Extra Fresh Hopped Nutcracker Ale that went through label registration in Missouri. This is a standard practice for Boulevard to get label approval for every beer they bottle or keg, no matter if it will be available for retail sale. This allows them to make it available at festivals with no extra problems.
Nutsack may be available in the tap room at Boulevard if you're lucky enough to be scheduled for a tour. It may also pop up at beer festivals or maybe even a beer dinner or two over the next couple of months. It's a great beer and should be sought out, but you're not going to be able to buy it anywhere other than the Amber Market*.
*The Amber Market is the beer black market, I'm coining this term and all proceeds from such coining are payable to me.