As Sony promised, they have released their 2.80 firmware update for the PSP. While they haven't updated the US Playstation website with the system update and change log yet, 0okm was able to track down the US, EU, UK, Australia/New Zealand and Japan eboots and they're posted on QJ's PSPUpdates. Here is a list of changes made in this release:
NetworkRSS Channel viewer now supposts video and image content.
Now possible to login to Location Free via a wireless access point.
Music
Support for AAC files with ".3gp" extension.
Misc
Play and save content in "MUSIC," PICTURE," and "VIDEO" directories on the Memory Stick Duo.
Adding the next downloadable game demo to the "Memory Stick Duo".
Download the eboots from QJ.NET if you wish to update your PSP to 2.80.
PSP System Update v2.80 US
PSP System Update v2.80 EU
PSP System Update v2.80 UK
PSP System Update v2.80 Japan
PSP System Update v2.80 Australia/New Zealand