iOS 7 is hands down the biggest update to iOS we have seen since the introduction of Notification Center in iOS 5. For the first time ever, every single one of iOS' core apps are getting a completely overhauled design.
In iOS 7, Apple has completely revamped what we'll be seeing in our main core apps. Messages, Mail, Calendar, and more will receive new translucent keyboards, new colors, and a design that manages to simply get out of the way and lets you focus on your content.
By using a series of grid-like guides, Apple has taken all the core apps from icon design to how you view them to a new level. That means your content is now the main focus, across all apps, with menus and text getting out of the way.
As we know more about each individual app, we'll be sharing it via our WWDC live coverage so make sure to check back often to see how each individual core app is going to change with the introduction of iOS 7.