The next production for the Agatha Christie Theatre Company is Go Back for Murder, which will be touring from January 2013:
Carla Le Marchant learns a disturbing family secret; her
mother, Caroline Crale, died in prison after being convicted of poisoning her father. Caroline leaves an intriguing legacy in the form of a letter professing her innocence and, believing this to be true, Carla is determined to clear her mother’s name. Suspects, secrets, and red herrings abound in this thrilling new production
I haven't got the full itinerary but early stops include Windsor, Malvern, Wolverhampton and Cardiff. Another non-comprehensive listing can be found here.
Apparently the play Go Back for Murder was adapted by Agatha Christie from her Poirot novel Five Little Pigs.