For the last year or two, Sony has been doing quite a job at releasing great handsets, and quite even, if not better. Although it is not so long ago that Sony just release the Xperia Z2, with IFA is coming soon, we already see some rumors about a new product that is in the work.
As you remember (If you do), the leaked model number D6603, which we are now known as the Sony Xperia Z2. Today, as the Indonesian Postal regulatory site shows us a new model of a Sony product, and that is the Sony D6653. With the two numbers so related, this must point to the successor of the Xperia Z 2. However, this is just a speculation, this can might be the rumored Z2 A, or other variants of the Z lineup. However, with the 6 month-life cycle that Sony is doing with its Xperia Z, it is no surprise that we will see the Xperia Z3 at IFA 2014 this year.
Source: Xperia Blog