Rumor is, Android L could support multiple user profiles, say one for you, and one for your kids. That means you won't have to worry about another person getting into places you don't want them to be. Ditto if you're the type who'd rather keep work and personal accounts separate.
A smarter, more social lock screen in Android L means you'll be able to see and respond to notifications without having to first unlock your phone. Android will safeguard your more sensitive information and will only deliver the most relevant alerts.
Cascading cards show you your recent apps, which not only looks cool, but also lets you see multiple instances of open apps, like separate Google Drive files and websites. All this leads to faster navigation as you switch tasks.
Between support for ART and 64-bit architecture, Android L improves the overall performance, yet still promises to still play nice with your battery. A built-in Battery Saver mode can also turn off unnecessary system functions.
This one's a boon for smartwatch owners, among others. Instead of entering a PIN on your password-protected phone every time you start looking something up on your watch Android L will let verified hardware bypass security to get you in faster.
Shhh! Silencing your phone overnight or for a short while or when certain people call will now be included Android. The customizable settings make it a simple way to avoid interruptions without totally silencing your phone.