After two sleepless nights and great help of iQD and PS3-690, finally the PS VITA .pkg xTractor application 1.00 is finished.
This program can decrypt & extract PS VITA game package (.pkg) files.
To use the program you need to place the PS VITA .pkg AES key in the same dir as the executable.
Funny as SONY is, they probably were to lazy to think of a new key and just used *hehe*, the PSP .pkg AES key.
Information tab not finished, yet. It will be completed in next version.
So just put the PSP .pkg AES key in hex syntax in aes.key file in the same folder and you are ready to go.
Another thing worth to mention is that thanks to GregoryRasputin the PS VITA developer wiki is now online.
For now it's near empty but I hope it will fill fast: http://www.vitadevwiki.com/