I quickly copied the following from New Holland's web site. We received the keg along with the rest of the shipment, and I wasn't sure if there'd be room for it, but Eric found a way. He also just went home, after being up all night getting the Gravity Head drafts in order.
So far, I've sampled wee bits of Marsha Mallow's, Blue Sunday, and Charkoota (original and rum barrel aged). All are excellent. I recommend doing the two Charkoota brews back to back; you can taste the rum in the barrel-aged version, without the burn, and with the smoke and rye blending seamlessly in the background.
New Holland Collaboration Brew
Marsha Mallow’s Malted Milk Stout 8% abv
Brewed with City Provisions (Chicago)
Brewed at New Holland Brewing Co. Restaurant and Pub with Chef Cleetus Friedman of City Provisions Delicatessen. Named after the infamous Marsha Mallow, of the NHB staff holiday party, 2012.