Sony's official PlayStation.Blog has revealed that PSP firmware version 4.05 will be released shortly. Eric Lempel, director of PSN Operations, suggested that the update focused on the device's music-playing capabilities:
"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."
Lempel stopped short of announcing those other features, but we should be able to find out for ourselves once the update is released. We expect that'll be before Sony's E3 press conference tomorrow, perhaps giving the company something to discuss during its keynote speech. Don't forget, PSU will be providing up-to-the-minute coverage of everything PlayStation (and more) from E3 this week.
UPDATE:
As the comments below show, the firmware update is available for download!

Wow, another almost useless update. Fun.
Although a few more visuals would be nice, as long as they keep in time with the music.
And, first comment, yey!
update is out already cause i found my psp and tried updating and at the time our ur writing it was available
Ah good as my PSP is just a glorified MP3 player these days, i wonder what the other features are???
LMAO..its been out for at least five hours before you posted this !! (Cause that's when I checked).
Why don't they give us more visuals for the PS3?
you lot are talking out of your bee hinds, just checked the sony website and the latest one available is 4.01
Downloaded it like 30 min ago, another useless update.
richkaos: I'd guess Sony hasnt updated their site yet
your right, pardon me, i just updated mine via the PSP and all is well, come on Sony update your site!!!
They need to fix Remote Play. That is exactly what I got it for, and my router doesn't work with the Remote Play feature, due to some "exception" found when you try to turn on the "Via Internet" option.
I shouldn't have to buy a new router, just to access my PS3.
Yes, I also vote for Remote play to be fixed. Not once have I been able to access it when I choose 'Over Internet'. Now if I'm in my house and I choose "Private Network" it works.
my remote play works perfectly w/ my linksys mimo wireless n giga edition router....120 bucks and its worth every penny. Now I can watch movies on the loo ! :) lol
I don't really use my psp for music anymore. I deleted all the songs I have on my memory stick and now use my ipod for music.
Wow. Epic fail. One new pretty lame vizualizer for people who use backgrounds(which im pretty sure is everybody)? Come on Sony.
@ 91761jimhoffa
Well the psp speakers are significantly smaller than your car speakers, that is why the cd's sound louder. If you put on headphones it sounds alot better. Or if you want, get an adaptor to where u can play your psp off ur car audio, thats what I have and it sounds great.