From your keyboard to God's in box.iOS should move from a big update once every year to once every 2 years (or every 1.5 years), and focus on stability and reliability.
They should also drop the idea of letting users remain on every main number version of iOS: this risks creating a fragmented environment, and especially to force developers to support older versions of iOS, which big developers (like Apple, Google, Facebook, etc...) can afford to, but little- and medium-budget developers can't.