Phil Spencer has gone from lowly Microsoft Game Studios corporate vice president to the pithier, more impressive sounding Head of Xbox. He's presumably replacing departed Chief Product Office of Xbox Marc Whitten, consolidating Whitten's title to a simpler, more commanding epithet.
Phil, Head of Xbox will also be consolidating Xbox (there can be only One). Spencer will be, "leading the Xbox, Xbox Live, and creative teams including Xbox Music, Xbox Video and Microsoft Studios." They'll all be under one man-shaped roof.
For an idea of where the head of Xbox's body politic might be leading it, check out this recap of his GDC chat, written up by Steven Hansen, Head of Features.
A New Day at Xbox [Xbox Wire]