This article says that Microsoft did another reversal because of all the hate and comments towards them for not including a headset. They will now include a headset based on rumors.
Source: Xbox One November Launch & Hardware Bundle Contents Confirmed [Updated] | Electronic Theatre
The Xbox One hardware bundle will now include the Xbox One console featuring a 500GB hard disk drive and Blu-ray player, the new version of Kinect, a HDMI cable, and a redesigned wireless controller in addition to a wired Chat Headset. This package will be available from an unspecified date in November 2013, with a recommended retail price (RRP) of £429 GBP.
Source: Xbox One November Launch & Hardware Bundle Contents Confirmed [Updated] | Electronic Theatre