Mrs. Mayer will have a hard time. While she may partly be behind the success of Google search product, she had been also for years the head of product at Google. And what successes did she have there? Has there been any other overwhelming success apart from Google search? Or have they just been throwing product over product to the wall to see which sticks?
Yahoo! itself is a dinosaur that basically has dying products. E-Mail? Still attracts eyeballs galore but is getting less important by the day. Search? Comes from Bing. Finance? Yawn. Flickr? Once a frontrunner in social networking, it has seen a slow death after several bad decisions since their acquisition by Yahoo!
Reminds me of the (equally) overvalued Tim Armstrong running AOL. Much praise, few results. Admittedly, Armstrong did not sink the company, so he must be doing something right.
I think that Mayer's results at Yahoo! will be similar despite all the praise. (Also, according to the linked article, she seems to be pregnant, and THIS may change her life A LOT. Probably more than she is willing to admit right now.)
But I agree with most analysts that Mayer is at least a glimpse of hope for Yahoo! I wouldn't bet the house, though, that she will be able to turn around the company.