Rollout includes data centers in Chicago, Manhattan
With some smartphone users turning into data hogs, AT&T eyes a 'pricing scheme'
Update will be phased in over the next week
Nook e-reader now slated to be available in Barnes & Noble stores after the holidays
The e-reader's two-screen approach takes some getting used to
Battle has underscored need to bolster networks to keep up with data-hungry apps
Execs want to deliver media content to screens large and small
Privacy, antitrust issues to be reviewed
Even then there won't be many available; Online orders also delayed to Jan. 11
