The 6S and 6S Plus are not that old, yet we hear about their successors. 

Research company TrendForce says that the next generation of iPhones will have 3 GB of RAM and will be waterproof. 

We have a lot of waterproof phones with Android, and not a single iPhone could survive under water, but this could soon change. 

The same source claims that we'll get some unveil durning the second half of 2016.