AT&T (NYSE:T) announced Wednesday that they will be the exclusive U.S. mobile broadband carrier for Sony’s (NYSE:SNE) upcoming two-screen tablet called the S2, which opens and closes like a clamshell. The S2 is set be released later this year.AT&T's Vice President, David Haight said the S2 is unprecedented" and "completely portable" design, offers "a convenient and unique entertainment experience."AT&T has a potential upside of 5.5% based on a current price of $30.77 and an average consensus analyst price target of $32.48.