You can enter a hidden service mode by powering off the unit fully (holding power), then powering on while holding R trigger, the PS button, and the power button until the service menu appears. Useful for formatting the memory stick, restoring the database, restoring the Vita to factory defaults, and a little more.
Yep - I've posted this a few months back - you can do the most of the function also in the Settings / Format submenu.
Yeah I noticed this too, kinda disappointing. Was hoping for some really cool stuff, but I could see it being useful in the future when someone reports they borked their unit somehow. Probably a failsafe for Sony tech support over the phone.