I missed this last week, but the Andrew Lloyd Webber Art Foundation, after winning dismissal of a New York action seeking to reclaim a Picasso painting it had been trying to auction off, has started proceedings in the British courts to confirm its ownership of the work.
UPDATE: Related story from Carol Vogel in The New York Times Saturday:
"In a legal strategy that is spreading in the art world, the Museum of Modern Art and the Solomon R. Guggenheim Foundation jointly asked a federal court yesterday to declare them the owners of two Picasso paintings that a claimant says were sold under duress in Nazi Germany. A request for declaratory judgment, filed in Federal District Court in Manhattan, involves 'Boy Leading a Horse' (1906), donated to MoMA in 1964 by William S. Paley, the founder of CBS, and 'Le Moulin de la Galette' (1900), given to the Guggenheim in 1963 by the art dealer Justin K. Thannhauser. The museums asked the court to declare that the paintings had never been part of a forced sale and rightfully belong to them."