The Vita looks nice but the market its aimed at it quite small and they probably won't get those mass market sales they need. The pitch they have for the Vita is the exact same as the original PSP.
Keep in mind the PSP sold 67.8 million units while the PS3 sold 50 million and Xbox 360 sold 55 milion. The DS easily outsold the PSP (DS - 146 million) but still, I wouldn't say the market is small.