Sony: Only One Playstation Network Account Per Vita
The poster says the information came from an FAQ sheet on Sony’s upcoming handheld device and was translated from Japan. In order to switch a Vita to a different PSN account, you’ll need to access the factory settings menu, which likely entails reformatting it (and wiping the memory). The big bummer there, of course, is that you won’t be able to share a Vita with another player in your household.
The single-region formatting also effectively region-locks the Vita until you switch out the profiles, which is surely problematic for some players wishing to get games from multiple regions, like Japanese imports that never make it across the Pacific. So if you were intending on enjoying regional content from around the world on your shiny new Playstation handheld, you might want to write your local Sony exec. Oh wait, Sony’s not a democracy — so you’re just screwed.