(Business 2.0) – Nintendo has long ruled the market for portable game consoles. But for the first time, its Game Boy is facing serious competition from Sony and Nokia. Nintendo is fighting back with its next-generation DS handheld, landing on U.S. store shelves Nov. 21. The $149 portable features voice-enabled and touchscreen controls, plus voice-over-Internet chat capabilities that are wowing industry insiders. Nintendo hopes to sell 4 million DSs by March, reestablishing its dominance right around the time Sony finally releases its first portable, the PSP.