Given that the Z3 Compact carries the internal coding D58xx, we can assume that the E5803 listed here is its successor. The one listed with a 68 prefix caught our attention, though, as that's the coding of the 2013 Z Ultra (C68xx), which, with its 6.4" display, and a thin, waterproof body, was pretty much ahead of its time.
Not anymore, though, as the ever-increasing smartphone screens show, so we can't wait to hear the actual specs behind this future Sony phones. Something tells us that Snapdragon 810 and 5.9" 2K displays might be in play here, too. As for the other two Sony phones listed here, and the actual release date, these are anyone's guess.