The MAY10 revision has been replaced by the AUG10 revision (batch #21). More information about the coverage can be found here.”
"The number of airport charts are now 27,441 (previously 26,972), in a total of 1,320 airports. The new and revised airport charts are distributed over 189 airports worldwide. Including this expansion of the coverage there are 60 updated enroute charts in total. The majority of the enroute charts covering Europe, South America and Asia have been updated."