PSP Official Firmware v5.00 Released
Just yesterday I wrote about the new shiny official firmware will be releasing soon, today is the day. After PS3 firmware v2.50 released couple of hours ago, now you can do the update from the Network Update icon in XMB.
Here are the changes from the official psp updates page (jp)

(PlayStation ® Store) is now available.
Using a wireless LAN, PSP ® directly from the additional items such as games and download games (purchase) is now available.
For PSP-2000
PlayStation ® format software images to a TV when you extend the functionality of the output.
PlayStation ® format software images can be output in full screen.
Connect your cable TV and video output in the case of interlaced, PlayStation ® format software to allow video Outputs.
Video
Types of files that can play videos that have increased.
Music
To the control panel (Sleep timer) was added.
Setting
(Video settings) [see title] has been added.
(System Settings) [USB Auto Connect has been added.
(Power-saving settings) to the automatic backlight adjustment] has been added.
Other
XMB ™ (XrossMediaBar) the background of the new.
Full-size keyboards are now supported.