Brothers and sisters, I have good news! As previously rumored, Apple’s upcoming iOS 9, when it ships in September or October, will run on the same iPhone, iPad and iPod touch models that run iOS 8.
iOS 9 Compatible iPhones:
— iPhone 4s
— iPhone 5
— iPhone 5c
— iPhone 5s
— iPhone 6
— iPhone 6 Plus
iOS 9 Compatible iPads:
— iPad Air 2
— iPad Air
— iPad 2
— iPad 3rd generation
— iPad 4th generation
— iPad mini 3
— iPad mini 2
— iPad mini
iOS 9 Compatible iPod touch models:
— iPod touch 5th generation
And, for what it’s worth, Apple’s 2015 desktop operating system is similarly forgiving and will run on the same Macs that are capable running OS X Yosemite, the current shipping version.
More info: iOS 9 Preview Page