This just in from Anchorman at the official site:
Good morning. We're very pleased to announce that Coldplay will be playing some outdoor shows in Europe in August 2009. The confirmed dates are below.
Tickets for all shows go on sale on Friday 12th December, apart from the Dutch gig, which is onsale now.
UPDATE: If you're signed up to either Eventim or Getgo with a Coldplay 'ticketalarm', you can reserve your ticket straight away. [thanks mc_squared]