sc94597 on 04 March 2015
Either nHD (640*360) qHD(960*540) or HD (1280*720) (depending on whether or not it has two screens.) If it has two screens I don't expect one of the screens to be much bigger than say the 3DS XL. So nHD or qHD would be fine. If it is one large screen (say Vita's size or even Phablet sized) I expect either qHD or HD.
Basically I expect the screen to be 200+ ppi for the sole reason that a screen that has less would be hard to find a manufacturer for (even the lowest res phones are like 250 ppi.) Vita is about 220 ppi. 3DS ranges from 90 to 125 depending on the version.
