Sarah Meiklejohn is a researcher now at UCL.  She is probably best known for her authorship of one of the best research papers in the digital currency space: A Fistful of Bitcoins: Characterizing Payments Among. Men with No Names.

She recently gave a presentation covering this paper (which admittedly has older data) and talks about some of the new privacy projects like CoinJoin which she says had a noticeable impact on a heuristic used in the study.  The Q/A session at the end also has some good comments.