Sony's not doing well in this battle against homebrewers. Although they just released 2.81 (to very little fanfare), the hacking community never seems more than a step or two behind. Firmware emulation has been an option for many people with 1.5 PSPs, as it gives them the flexibility of running all homebrew, while accessing the latest games and features of Sony's official firmware upgrades. Dark_AleX has decrypted firmware 2.80, which will theoretically allow those with DevHook to emulate firmware 2.80. DevHook hasn't been updated to support the firmware, and with Sony keeping a close eye on the program, who knows how long it will take?
I'm assuming the talented homebrew community won't take long. Already, it appears that 2.81 can also be successfully decrypted using the same methods.
[Via PSP Hacks]