Xbox wants the next-generation of gaming to coincide with your mobile devices (and actually matter). Smartphone and tablet users will be able to control multiple aspects of their Xbox One experience including IGPs (in-game purchases), setting up multiplayer matches, and starting a single player experience. At today's E3 press conference, Xbox utilized new titles and a tablet to showcase some features: Killer Instinct with twitch video sharing, Dead Rising 3 and calling in a massive artillery strike, and Ryse with tracking game and stage progression.
Xbox did a semi-decent job explaining the potential uses of Smartglass on-the-fly while in gaming action. The best news of the day was the smorgasbord of games coming to the console; this will ultimately lead to highly improved uses of Smartglass, if, Xbox has any interest in making it a relevant next-gen feature.