Note see for in depth (technical) coverage a follow-up post on this subject.
User and bot activity levels (bot = automated edit tool) are now reported in much finer detail and with more specificity.
A revised scheme for counting newcomers on the projects gives a more balanced view on the resilience of the editing community.
Added July 20: The line chart above shows same data as bar chart below.
Added for easier comparison with other charts.
Monthly arrival of new wikipedians on English Wikipedia. Chart resized to fit, see full size version