Thanks to Jacques and Mourad for the information. Keith Jarrett's next album will be a 3-CD set entitled "Testament (Paris/London)". It will be released in late 2009 (probably October, but this is subject to change). It will probably include parts (or the entirety?) of two solo concerts from last year:

• Salle Pleyel, Paris (November 26, 2008)
• Royal Festival Hall, London (December 1, 2008)

Jacques adds that, according to an interview published in Jazzman in 2005, "Testament" is the name Keith Jarrett originally wanted to give to "Radiance". It probably says something about the quality of the music on "Testament" (at least from Keith Jarrett's point of view).