As quoted from Eric Lempel from the PlayStation Blog:
"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. Enjoy!"
These music player visualisations sound like good fun, not too sure what he means by 'among other features' though perhaps some more PS3 PSP connectivity or access to the Playstation Store, or just the usual routine extra security/stability issues.
Hopefully the guys at M33 will be able to work their magic soon with this latest firmware update upon its release.