ethomaz on 08 December 2011
FAIL
http://www.wired.com/gamelife/2011/12/vita-accounts/
Multiple PSN accounts is possible on PS Vita 
.
"Your PSN ID is bonded to your memory card and your memory card is bonded to your Vita,” MacKenzie said. “So if you wanted to change different PSN users but use the same memory card, you would need to go factory reset.”
The account is stored in memory card... so the Vita can use witch memory card you want... one account per memory card.
