We stumbled across a bunch of leaked videos detailing the features of Moto X, like a promo for Rogers, which says the handset will be hitting Canadian shelves in August, so we'd assume the same for US. The ad also touts the always-on environmental awareness of the handset that listens and answers to you all the time, not only in unlocked state...
Source: http://www.phonearena.com/news/Watch-the-first-Moto-X-promo-and-hands-on-videos-here-coming-in-August-always-paying-attention_id45915
Source: http://www.phonearena.com/news/Watch-the-first-Moto-X-promo-and-hands-on-videos-here-coming-in-August-always-paying-attention_id45915