ArsTechnica reports thatEMI's DRM Free tracks on iTMS Plus are selling VERY well with double and triple digit percentage increases. As ArsTechnica points out, some of the increase could be a result of users looking to upgrade already purchased tracks, but that still means that users are willing to pay the extra 30 cents to loose the DRM.
EMI execs are expressing confidence that the trend will continue, and other labels are considering joining them, probably when more data has come in.