http://blocktrades.us has added pairs for purchasing DVS with BTS and BTC. Since there's no official feeds for DVS, we just set an arbitrary exchange rate of 1 BTS = 10 DVS.
This isn't intended to set any real economic value on DVS, we just wanted to setup a simple mechanism for easily obtaining small amounts of DVS for testing purposes and for generating DVS transactions to DevShares accounts. In particular, this is definitely not recommended as a method of acquiring DVS for speculation purposes and there's no reverse flow that supports buying anything with DVS on blocktrades.us...