Yay! We didn’t know this before, but Sony has confirmed it. The 1.60 PS3 firmware update will include Bluetooth keyboard and mouse support. This was mentioned in the BC press release. Here is the relevant portion:
Firmware Version 1.60 also delivers a more convenient process for downloading content to the PS3 from the PLAYSTATION Store. Up [...]
"1.60 Includes Bluetooth Keyboard and Mouse Support!" - 20.03.07