Firmware 3.15 which came out in early December 2009 is now mandatory to install. The firmware is needed for many new and upcoming titles, though most of you probably already have it installed. If you have already installed the latest update, this new does not affect you. Gamers who haven’t updated will be prompted to download it when they boot up their PS3.
In addition to adding the PS3 Transfer Utility and PSP Minis support, the update also improves system stability during use of some PlayStation 3 software.