A third European concert with the trio has been officially announced: Keith Jarrett, Gary Peacock, and Jack DeJohnette will play at the Gran Teatro La Fenice in Venice on July 16, 2013. Tickets should be available soon from ticketone.it (on-sale date currently unknown).
Thanks to Håvard for the information.
Update (February 7, 2013). Tickets are now available from ticketone.it. Thanks to Bren for the update!