The idea of having a screen full of icons, representing independent apps, that need to be opened to experience them, is making less and less sense. The idea that these apps sit in the background, pushing content into a central experience, is making more and more sense. That central experience may be something that looks like a notification centre today, or something similar to Google Now, or something entirely new.
The primary design pattern here is cards. Critically it’s not cards as a simple interaction design pattern for an apps content, but as containers for content that can come from any app.
The idea of cards, taken to the next level … “the notification is the interface”.