An hour or so later, Mayer announced on Twitter that she and her husband are also expecting their first child, a boy, in October.
Quite a day!
By all accounts, Yahoo's a mess. It's one of the original Internet giants but has become synonymous with bureaucratic bloat and repeated missteps over the past decade. It still has an impressive total of over 600 million users but, like AOL, is seen as a company whose best days are behind it.
I've admired Mayer for years. I've met her at conferences on a couple of occasions and was impressed with her easygoing, personable style. She's undoubtedly one of the brightest stars in tech and Yahoo's pulled off quite a coup in landing her.
The question is: is it too late for Yahoo!?
Marc Andreeson, a pretty solid source, says he thinks it's not, but that Mayer would have to begin by cutting about 10,000 jobs.
Maybe more important than who she lets go will be who she brings in? Changing Yahoo's culture will be a massive undertaking.
I was impressed by the amount of positive reaction on Twitter yesterday when the news hit. Having a woman at the helm of one of the Internet's biggest brands brought out lots of support.
But the job is huge. I'm not sure it's doable. It may be that no one can save Yahoo!
What do you think? One year from now, what will we be saying about Marissa Mayer's quest to save Yahoo!?