On page 333 of the March 2010 issue, John Baez wrote that "MathOverflow has become a universal clearinghouse for math questions."
The March 2017 issue features an interview with Prof. Ken Ribet--the current president of the American Mathematical Society. At one point of the interview, Prof. Ribet expressed the following:
It’s clear that one of the challenges for the AMS now is to continue to maintain its relevance in a context where young mathematicians are using technology to share and gather information with less of the formal structure that older mathematicians like myself are used to. People ask questions and get answers on MathOverflow...
I suppose these are not the only two instances in which MathOverflow was brought up in the pages of the Notices... If so, would you be so kind as to enter below those mentions of MO in the Notices that you recall?
EDIT. For some godforsaken reason, I was leaving out the "opinion" on MathOverflow authored by A. Geraschenko, S. Morrison, and R. Vakil which appeared in the June-July 2010 issue: