Need for more PS4 info after news about the companion app and day one 1.50 firmware update popped up earlier today? SCE President Shuhei Yoshida just tweeted a link to the system's official FAQ, which answers questions users might have about game sharing and how friends lists work across the new system and older PS3s. As Sony was kind enough to point out during E3, game sharing on discs is simple and familiar. When it comes to downloaded games it's all about which system is designated as your "primary" PS4, which is where content you purchase through the app will automatically download, and is the one that hooks up to your PS Vita. Only one system can be your primary system at a time, and as long as your games are on that console, any user can play them or enjoy your PlayStation Plus features. It's similar to the current experience on Xbox 360, with an added bonus because your account can be in use on two systems at the same time.
Your PlayStation Network account will still work on other PS4s, but if you download a game there, only your account can play it. Switching to a different console as your primary is also possible, as long as you deactivate the current primary first. The other issue is how your new friends list will work across devices. On the PS4 you can have up to 2,000 friends, but the PS3 will only display 100 of them. If you're mobile, your Vita or PlayStation app should be able to display all 2,000. If there are any questions left, hit the FAQ and take a look.