According to an ad in the December issue of DownBeat (digital edition), ECM Records will soon release a new album, "Hamburg 72", with Keith Jarrett, Charlie Haden, and Paul Motian. This is probably a recording of the June 14, 1972 concert recorded at NDR Studio 10 in Hamburg, broadcast at multiple occasions by Norddeutscher Rundfunk (NDR). The concert last about 90 minutes and parts of the concert were previously released on an LP called "NDR Jazz Workshop '72", so this could be a very interesting release.

Manfred Eicher and Jan Erik Kongshaug mention that the recording will be remixed from the original tapes.

Thanks to Peter for the information!

Update (November 4, 2014). ECM Records now features photos of Keith, Charlie, and Paul (probably from the Hamburg 1972 concert) on its home page. Thanks to Christoph for pointing it out to me.