Now that Marissa Mayer is at the helm of Yahoo, I have just one hope for Yahoo. That they not waste their time and resources trying to build a mobile phone or social network. They are huge and diverse already, to the point where nobody knows if they are a tech company or a media company. They have an almost 0% chance of winning either and Yahoo has a ton of important work to do if it wants to turn itself around. It would be nothing more than a distraction.
It will be interesting to see what happens. Her first mission should be to fix the culture that killed Flickr. Unless she does that, Yahoo is a lost cause.