Maybe you noticed the PS3 uses mini-USB to recharge everything: Sixaxis and/or DualShock 3 controller; official Bluetooth headset; and even the soon-to-be-released Wireless Keypad. If you want to extend your gaze outside into the larger PlayStation family, the PSP-2000 and -3000 also support charging over USB. Convenient, no? What's not as convenient? A distinct lack of mini-USB outlets in our homes.
Cue: the official PlayStation "AC Adaptor" available at retailer this December for $25. You plug it into one of your many "AC" outlets and it converts all of that alternating current into sweet, delicious, USB-shaped direct current. Considering that the PS3 itself will charge your gear, we can only assume the target demographic is those of you that don't turn it on.
... But if you don't turn it on, why do you care if its peripherals are charged? Alright, we admit it. We don't know who this is for.