The new iOS 8 by Apple will roll out on September 17, 2014.
Along with the iPhone 6, iPhone 6 Plus and Apple Watch, Apple also announced the release date of the newest iOS on September 9, 2014. iOS 8 will have a public roll out on September 17, 2014. The iOS 8 will be compatible with:
iPhone 6 Plus
iPod Touch 5th generation
iPad with Retina Display
All iPad Minis
As for the design, iOS 8 will retain the same design as the iOS 7, but will have significant software improvements. TechRadar stated that Mac OS X Yosemite will have be integrated better with the iOS 8 and the iOS 8 will loosen the restrictions that iOS 7 placed on the TouchID fingerprint sensor, which will open up an array of new uses for the technology.
Along with the security bypass and for buying stuff from the App Store, the TouchID sensor can be used by apps for other things. For instance, a banking service, Mint.com, is currently in the works to make the TouchID scanner as a means for authorization of payments.
iOS 8 will have support for 3rd party keyboards, with SwiftKey already having unveiled their keyboard for the new OS.
The biggest and most significant addition to iOS 8 will be the Health app. The app will let people keep a log of their daily nutrition, their sleep, fitness and body measurements. This will be a great feature when coupled with the Apple Watch that is slated for release in early 2015.
A better review of the iOS 8 will only be possible when OS comes out on September 17, 2014.