Sony's Xperia Z line of devices may not be the most available handsets out there, but they have always been great products, and given your taste in design, they may have even been some of the best looking devices available. That is all in the eyes of the beholder though, so we won't be making any judgments in that regard. Whatever you have thought about the design of the Xperia Z, the Xperia Z2 and Xperia Z3 line of devices, one thing appears to be a great possibility and that's the fact that Sony may not be looking to deviate too much from their main design queues.
According to some of these concept images that have surfaced(leaked?)and have been found inside of internal emails from Sony Pictures Entertainment, the Xperia Z4 in one concept looks to some degree like its predecessors, but with renewed life in a few places. The emails which Gizmodo points out were part of a product placement pitch for the upcoming James Bond film set to release next year called Spectre, talk about Spectre's main actor, Daniel Craig garnering a $5 million fee to be shown on screen with the product. That isn't the important detail though, what is important is the first image titled The Elemental with the words Xperia Z fourth generation below it. That image points to the possibility that these are all concept images of the upcoming Sony Xperia Z4 flagship that Sony is supposed to be showing off at CES 2015, which is just in a matter of weeks.
Another concept image shows what would appear to be a different Xperia Z4 design made up almost entirely of glass, with notes of a 1.2mm glass panel, a mirror front/back, and resin bezels. Another concept shows off three different colored phones, with the concept of having the color of the metal frame changing colors from the lock screen with a matching clock. We're not sure how that would look or how Sony would implement it, but it sounds like an interesting feature. Whether or not we see anything that looks like these concepts in come CES is unclear but CES isn't too far away so we could end up finding out exactly what the Xperia Z4 looks like soon enough. You may also want to go back and watch the teaser video thrown out officially by Sony mobile from this morning which you can find here, which starts off with someone picking up a rather thin device that could be the Xperia Z4, and then proceed to hint at the coming of Lollipop and Material Design, at least that's what I gathered from it with all the use of bold, vibrant colors.