I think it is going to get very messy, especially if she manages to make any successful changes in Yahoo. The big thing to watch, as a I mentioned earlier, would be Social Media moves. G+ is not exactly successful and it is like Dear Leader Larry and Google have almost bet the farm on this beating Facebook. However it hasn't so far and with Microsoft being involved with both Yahoo and Facebook to varying extents, Google has some real reasons to be worried. FB's COO, Sheryl Sandberg, is also an ex-Googler so perhaps Google is afraid that Marissa Mayer could have a similar level of success at the expense of Google.