On the same day PlayStation Vita launched in Japan, hackers managed to find and use an exploit that allowed them to run unsigned code on it.
The first "Hello World" homebrew application was released a few hours ago by Japanese homebrewer, Mamosuke.
But this is not a silver hacking bullet. In fact, Mamosuke used a buffer overflow exploit in the PSP emulator on the PS Vita to run his code. In other words, Mamosuke has found a way to run unsigned PSP code on the PS Vita PSP emulator.
This doesn't mean that PS Vita is hacked or that pirated PS Vita games will be playable any time soon. It means however, that the current library of pirated PSP games can be made playable on the PS Vita through its hacked emulator.