I know we've discussed the Mrs. vs. Ms. debate before. Here is an interesting twist from the Wall St. Journal's Wall St. Journal's Style and Substance Blog:

German Chancellor Angela Merkel is to be Mrs. Merkel in second references in our pages, at her request, as an alternative to Chancellor Merkel. We had been using Ms.

Her staff indicated that she was following the model of Mrs. Clinton in choosing Mrs. over Ms. or Miss. Unlike Mrs. Clinton’s, however, her surname is that of a previous husband; her current husband has the surname Sauer. Of course, she is also Chancellor Merkel.

The Germans themselves don’t have a problem in deciding between or among honorifics for a woman nowadays because they have generally adopted the use of Frau for all women.