PS3 Firmware 2.60 Live
Sony has rolled out with firmware 2.60 today. Despite the release of USBAdvance, it is currently unknown if the method is patched yet (but we are assuming it is not).

Firmware 2.60 brings the following new features:
Guest access to PlayStation Store – This enables non-PlayStation Network members to browse through the storefront to check out the latest games, demos, videos, etc.
DivX 3.11 support – Videos in this format can now be played on PS3.
If you are skeptical and eager to try out the PS2 backup booting on your PS3 it is advised to not update yet until we get confirmation of this method working on 2.60.

UPDATE: Here are some (unconfirmed) hidden updates Sony convinently left out for us:

Safe Mode
Blu-Ray Disc Theme Support
HDD Data can be accessed and deleted in-game
3-D Secure Support
Improved System Stability