Chief data officer
Sure, an acquisition will give Microsoft access to Yahoo's extensive user database. But if they need someone to make sense of those numbers, then they'll want to keep Fayyad, a former rocket scientist who now oversees Yahoo's data strategy. Data mining is also key to using behavioral targeting in advertising. Fayyad is no stranger to Microsoft though -- he did a five-year stint leading the company's data mining research group way before coming to Yahoo. But it's not clear whether he's eager to work for the software giant again.