UPDATE: According to the source listings on Wikipedia, the only changes in PS3 firmware 4.40 include improved system stability and fixed issues with certain games.
Hot and fresh out of the Sony kitchen is an official, but slightly spontaneous, firmware update for the PlayStation 3.
It seems spontaneous, because firmware 4.40 wasn’t detailed or announced prior to its release. However, it’s been confirmed by PSNStores via Twitter that the update is mandatory. Since it is mandatory, it could simply be to strengthen the PS3 software to avoid any potential exploits found by hackers and jailbreakers. This is purely speculation, and Sony will more than likely not detail the specific reasons validating the update, but Sony is good to detail what updates change.
Once we know for certain what the firmware update changes or enhances, we’ll update this thread.