PSP Firmware v6.10 has been hacked! The door is semi open for homebrew on the PSP!Go. A proof of concept video has been released via YouTube. The used exploit is yet undocumentated and unreleased.

Source: http://wololo.net/wagic/2009/11/12/firmware-6-10-hacked-with-kernel-access-psp-go-poc-video-by-team-typhoon/

http://www.youtube.com/watch?v=9lVCV1LGHiA