Vita.
Sony has continued to make statements about not making games for it and expecting 3rd parties to carry the weight

.Add that to Nintendo owning the handheld market, Smartphones/tablets eating into that market, Japanese publishers transitioning onto making phone games as well as Western publishers not caring about handhelds and its a really tough sell. Not to mention those atrocious propriety memory card prices they refuse to move on.
Its a damn shame too because I fukked around with a Vita for a while when my lil bro copped one for the holidays and its a nice piece of hardware. I'll probably be picking one up when it hits $99.