48 hours is all Sony needed to push more than a quarter million PlayStation Vita's. It doesn't sound like a lot, but 321,400 is a great achievement for Sony.
Comparing them to Nintendo, they should be proud. Nintendo's much advertised 3DS only sold 50,000 more units, but then sales dipped. The sale numbers were only saved with a price cut. For the PS Vita to continue its success long-term, it's going to need some smash hit, killer apps. Something that hasn't been done before, something that pushes mobile gaming boundaries. If I were in charge of the Vita, that's the kinda target I'd have.
Have you managed to get a PS Vita? If so, please do let us know how you've gone with it!