During the WWDC 2014 keynote, Apple wrapped up its overview of iOS 8 and has officially announced device compatibility. This release is available for developers today and schedules for a public launch in fall.

iOS 8 will be compatible with iPhone 4s, iPhone 5, iPhone 5c, iPhone 5s, iPod touch 5th generation, iPad 2, iPad with Retina display, iPad Air, iPad mini, and iPad mini with Retina display. So it looks like the iPhone 4 is officially dead to Apple.