Leica released the following invitation:
"Leica celebrates the essentials of photography! We invite you to exclusively experience a whole range of product launches in a culturally and photographically unique atmosphere on 10-11 May 2012 in Berlin..."
It was generally expected that the M10 would be introduced at the photokina in Cologne this fall along with the rumored mirrorless camera system which is expected to allow the use of Leica R lenses along with its own line of lenses. But then Leica can be quite particular with the announcement of new equipment. For example, the M9 was introduced on 09-09-09. May 10 appears to be in line with that practice. The Leica M10 on May 10 appears to be a distinct possibility.
Postscript September 18, 2012
To see what the rumored M10 actually turned out to be, go to;
THE NEW LEICA M