No mention of this 'new feature' was made on the AN.ON web site, though the phrase "Due to recent events, we would like to be sure to point out, that the JAP software is in development and therefore does not yet offer maximum protection." could be interpreted as a warning to users, especially given the colour (red) and the prominent placement on the web page.
It emerged that AN.ON had been ordered by a court order to log accesses to a particular web site (and also ordered not to tell their users). Though they claimed that all other accesses were still secret, the whole episode is likely to have sowed a lot of mistrust in the minds of their users. Since then, the monitoring function has been disabled again by order of a higher court, with only one single access to the relevant web site having been logged.
Since then, the AN.ON project has been waiting for the courts to finish deliberating about the legality of the original court order. It seems, however, that the officers of the Bundeskriminalamt (Federal Criminal Investigation Office) got tired of waiting for the courts to make up their minds. They obtained a search warrant and raided the private home of the Director of Systems Architecture at the Computer Science Department of the University of Dresden. He handed over the record in order to avoid, as he put it, "more large-scale damage" that would be caused by having the Computer Science department itself (home of AN.ON) searched. The members of the AN.ON project are understandably upset (link in German).
It used to be said that "on the net nobody knows you are a dog", but it turns out they can find out your breed and the number on your collar if they really feel they need to. It appears that not much has changed since the anonymous users of anon.penet.fi, the 1990s email anonymiser, found out they weren't all that anonymous after all.