There's a device out there in the wild by the name of Honami - code-named by Sony for their next-generation follow-up to the Sony Xperia Z, complete with specifications made to out-do the previous model. This device appears today in a series of hands-on photos snapped by an intrepid Sony even-goer in China. These images have subsequently been deleted by said user, suggesting therefor that they should not have been captured in the first place.
While the original image link is now a 404 forever, the Digi-Wo forum post can still be found. These images show the device to have a rather similar size, shape, and makeup as the original Sony Xperia Z, here coming with the specifications tipped several times over through the past several weeks.
Oddly enough, this device is said by Hardware Zone user Sephirot to be working with a body that's heavier than the original Xperia Z. This would indicate that the device is either working with more solid innards or a larger battery - we're guessing its the second option.
It's also said by this user that the Z1 works with a display that's brighter and slightly more "white" than the Xperia Z, working with X-Reality technology making the colors slightly less saturated than those devices working with Sony's Bravia Engine 2. It should also be noted that the unit this user is working with is an early edition with "X.XX" on its back instead of final megapixels written in under its camera lens.
This Sony Xperia Z1 is tipped to be working with a waterproof body - as tipped by Sony - as well as a much-improved camera over the Z. The Z1 is also rumored to be part of the waves of devices appearing at IFA 2013 with a Qualcomm Snapdragon 800 quad-core processor under the hood - that'd mean multi-mode LTE and carrier compatibility for essentially every mobile brand in the USA (and abroad, for that matter), right out of the box.