Nintendo has yet to commit to an official launch date for the 3DS portable. In an E3 interview with IndustryGamers, Nintendo of America President Reggie Fils-Aime promised that the device would launch in all major markets by the end of Nintendo's fiscal year next March. That, however, did not rule out a potential Christmas launch here in the U.S., and indeed, one U.K. source recently claimed to have knowledge that the 3DS would launch by the end of the year.
That's starting to look doubtful now, though, as Reggie has made an appearance on Late Night, and he told host Jimmy Fallon that 3DS would launch "next year." He didn't provide an exact date or even a specific month, so we'll just have to wait until more official information finally trickles out.

