The latest system update, 3.5 (Codenamed MUSASHI) goes live on PS4 tomorrow. It brings quite a number of new features to the console:

Appear Offline- If you’re one that doesn’t like to be bothered by other players, you’ll be able to change your status to offline.

Friend Online Notification- This feature will give you an on-screen notification whenever a friend gets online. It’s a feature that we’re all familiar with by now but it’s good to see it finally make its way to the PS4.
User Scheduled Event-You’ll be able to schedule gaming events with friends, perhaps scheduling a Mortal Kombat Tournament or a round of Black Ops. Players that have registered for the event will be automatically inserted into it whenever the scheduled date/time arrives.
Play Together- Allows all members of a Party to see what each person is playing so that you can easily join a friend’s game, or start a new game together.
Remote Play- Stream your games to the PC/Mac.