Sony have revealed via their official blog that firmware 4.05 will be released soon.

Eric Lempel, Director of Network Operations said "I wanted to give a quick heads up to everyone that a new PSP firmware update, v4.05, will be released soon. We know that more and more of you are listening to music on your PSP, and this update will add new visualizers for music playback, among other features".

We will let you know when the firmware appears and what new features it brings with it.