Sony announced the Xperia XZ at the beginning of this month. It will replace the Xperia X Performance as the company's flagship smartphone after just a few short months of that device being available.
Speaking of availability, the Xperia XZ will arrive in stock in the US on October 2. It will be sold by retailers such as Amazon and Best Buy, and its recommended price is $699.99. Obviously for that amount you'll get an unlocked unit, which will work with GSM-based networks such as AT&T and T-Mobile (and all MVNOs operating on their infrastructure).
Expect the XZ to go up for pre-order soon, joining the X Compact which was announced alongside it. The smaller handset will be out sooner, though, on September 25. Sadly the Xperia XZ won't have a fingerprint scanner in the US, continuing an unfortunate trend for Sony's smartphones.