Just swung by there today, on the corner of Summer and Washington. Not much to look at from the outside, but a few interesting vendors. On the edible side, there's a frozen farm-raised meat stand (Stillman Farms, I think) which had some nice looking beef and lamb products. A few bakeries, including Swissbakers. They had an interesting Swiss Christmas voodoo-doll bread, which I may pick up at some point.
The only thing I've tried so far was the Berliner (at the Swiss place), which was excellent. The guy at the booth laid it on a bit thick, though the same can't be said for the raspberry filling. Very tasty, however, and fresh. I may hit it tomorrow morning for breakfast, though the fillings change each day.
The website is at: http://dtcholidaymarket.wordpress.com/