iOS 9 & The Future
According to 9to5Mac's Mark Gurman, Apple has "restructured its software engineering process to better support older hardware." He claims that Apple might even release the iOS 9 update for the iPhone 4s, a device that was released in 2011.
This is big because it means that Apple might be looking to keep iPhone 5s software support around for more than three years. It also could mean that we won't see the same type of iOS deterioration that we often see as devices get older.
That would make the iPhone 5s extremely attractive if Apple decides to drop the price when the iPhone 6s arrives. We should find out more during WWDC 2015 in June.
Of course, we'll probably see Apple tack on some unique iOS 9 features to the iPhone 6s and iPhone 6s Plus though we probably won't hear about those until much later this year.