From Sony Blog:

The system software update 1.50 is approximately 300 MB, and will include the following features:

• Remote Play
  Users will be able to access PS4 titles displayed on their living room TVs and play them on a PS Vita system over Wi-Fi networks by using PS4 Link.

• Second Screen
  Users can use the PS4 Link application for the PS Vita system, and PlayStation App for iPhone, iPad, and Android-based smartphones and tablets, to use these devices as second screens in supported titles.

• Record, take screenshots, and upload gameplay effortlessly
  The PS4 system provides dedicated, “always on” video encoding systems that enables seamless uploading of gameplay.

• Broadcast and spectate gameplay 
  The PS4 system also enhances social spectating by enabling users to broadcast their gameplay in real-time to game fans around the globe, using Ustream and Twitch live internet streaming services.

• Play as you download
  This feature enables users to play supported digital titles as they are being downloaded.

• Multi log-in
  A maximum of four users can log-in to a single PS4 system simultaneously. These players can use their own save data to play games, and also earn trophies on their own Sony Entertainment Network accounts even when playing a multiplayer game together on a single PS4 system.

• Party (Voice chat)
  By using the Mono Headset bundled with the PS4 system, users will be able to chat with up to eight friends enjoying different applications or games. Furthermore, users can use Party to chat between PS4 and PS Vita systems.

• Face recognition and voice commands
  Users with PlayStation Camera will be able to register their facial image onto their PS4 system, and login to their system using facial recognition instead of DualShock 4.

• Background music player
  Users can enjoy gameplay while listening to music in the background with Music Unlimited, a cloud-based digital music service. Users can also voice chat with friends while listening to music.

• Online Multiplayer
  PlayStation Plus members will be able to play PS4 titles online with other players via the network. PS Plus makes it easy for members to join available online multiplayer matches in a variety of ways, including the ability to easily join a game from a live stream broadcast or Party voice chats.

• Blu-ray Disc and DVD player
  Users can enjoy not only gaming on their PS4 system, but also Blu-ray and DVD video contents. When using for the first time, users must connect to the internet to activate this feature.