Also while I was away, a "poet, actor, photographer, and makeup artist" named James R. Miller filed a lawsuit against the Mapplethorpe Foundation (and others) claiming copyright ownership in four Mapplethorpe works created in 1979. Benjamin Sutton has the details here.
The first hurdle Mr. Miller is going to face is the statute of limitations: he claims to have known the photos were attributed to Mapplethorpe since 1988, and that he has "attempted several times over the last 27 years to correct the historical and artistic record."