Underground has launched yet another venture. I stopped in yesterday, opening day, to check it out.
They are currently offering a well-curated selection of cheeses (lots of bloomy rinds at the moment), a rotating selection of fresh meats (chicken, pork, lamb and beef) and sausages, cured meats and daily lunch specials. There are some other things for purchase, but like Liz B said, the pickings are slim.
I chatted with one of the collective owners for a bit and learned that they are waiting on a license from the USDA to offer canned goods such as pickles and jams as well as a license to sell beer and wine. They also are very willing to work with the customer for custom meat orders because they're butchering whole animals. As far as I know, that is pretty unique to the downtown/near east side.
Even without the full smattering of offerings, the store seems very promising. The meat prices are reasonable (certainly cheaper than Whole Foods and about the same as Willy Co-op), the selection - though small - is well thought out, and Underground makes some tasty eats.
I will definitely be back soon and again when everything is up and running. Go check it out!