he PS4 UI takes a more social approach to the PS3’s XMB, beginning with the login screen. At first boot-up, players are presented with a view of all of the available player accounts, which are represented by a large, high-resolution image — whether it be a picture of the player or an icon. If you’re the sole user, you can configure the system to boot directly to the main interface, of course, but they’re giving multi-user systems a better gateway. For those that purchase the PlayStation Camera, the system also supports facial recognition. Players will go through a one-time calibration wherein the system snaps multiple views of your face for streamlined identification. In order to eliminate false or unintended logins, the system also requires players to raise the DualShock 4 into view as an added security layer. The PS4 also introduces guest accounts, which allow friends to create a temporary user account on the system that erases itself after they sign out.
Speed is the most noticeable improvement with the PS4 OS. Whether you’re checking out a video, loading the browser, or opening up a party chat, the system loads each function almost instantaneously. Games, on the other hand, are expectedly slower to load given the large file sizes. The home button on the DualShock 4 not only provides a shortcut back to the dashboard, but can also be used for multitasking, moving swiftly between your two most recent apps. Whether you’re playing a game and want to refer to a guide on IGN from the integrated browser, just double tap the home button and it will bring you back and forth between the app and your game.
Most importantly, messaging and chat is cross-platform, allowing players to communicate across PS4, PS Vita, and any smartphone or tablet compatible with the PlayStation app
Sadly, captured clips can only be shared from within the PS4 OS and the raw footage can’t be exported to a USB HDD or thumb drive, though Sony says it is considering adding the future at a later date.
As for the PSN Store, Sony has once again adopted a rather image-heavy design. On day one, every game and every piece of content you can buy in-store can be purchased digitally through the PSN. You can buy and download full games or you can redeem Sony’s promotional pricing for current- to next-gen title upgrades. If you bought Assassin’s Creed 4: Black Flag on PS3 and it came with the next-gen upgrade voucher, you can enter the code and get the reduced $9.99 pricing. More importantly, for select titles, you can choose to prioritize the download of certain modes or content so you can start playing faster. In our demo, Sony used Call of Duty: Ghosts as an example, which enables players to download the multiplayer suite first and the singleplayer campaign later.
A lot more here: http://www.ign.com/articles/2013/11/12/playstation-4s-interface-and-features-revealed
