The Digital Reader

From the press release:

AT&T’s fourth-quarter subscriber gains also reflect strong growth in wireless connectivity for emerging devices including eReaders such as the Amazon Kindle, the Sony Reader Daily Edition™ and the Barnes & Noble nook. Total emerging devices on AT&T’s wireless network increased by more than 1 million in the fourth quarter, its strongest quarter in this category to date, predominantly reflected in reseller subscriber totals.

That number probably includes more devices than just ebook readers, but not any type of phone (those are discussed elsewhere).