Microsoft paid $1.2 billion to acquire Yammer, an enterprise social network company. Yammer's got a lot of users -- and Microsoft plans to use that base to make the Office suite more useful.
The three dominant themes investors should watch for in the coming year
$102 million: Stephen J. Hemsley, UnitedHealth Group Inc.'s Chief Executive Officer. A graduate of Fordham University, Mr. Hemsley was Managing Partner and Chief Financial Officer of Arthur Andersen before taking the helm of UnitedHealth Group in 2006.