So she was head of Search at Google at one point right? I wonder what it would be like to become CEO of a company who has outsourced their whole search and advertising stack to Bing. Will Yahoo! start caring about search or ads again?
I wouldn't bother. They are so far behind both Bing and Google that trying to play catch up in the search game is simply a lost cause. They have significant traffic and brand loyalty for certain services (finance, sports, etc). They need to focus on that, not chase a game they lost ages ago (search).
IMO Yahoo's best bet is to reinvent themselves as a world-class product company, and rent the relevant tech stack from someone who can actually do a good job of it.