Haven't seen tried it yet. Looked it up on the Surley website:
BRETT DARK ALE/SOUR
SEASONAL BOTTLES AND KEGS (MARCH)
100% Brettanomyces dark beer, fermented in stainless and aged in used red wine barrels. “Brett†is a unique yeast strain that produces flavors that would be offensive if they weren’t intentional. Flavors of sour cherry, tobacco, oak, and classic “Brett†barnyard funk, balanced by Dark Munich malt chewiness. Enjoy immediately or age at cellar temperature for a couple years.
Don't know what it means but count me in.