Nintendo has not officially given the Nintendo 3DS a release date. The company has only stated that the Nintendo 3DS will be out before April 2011. It could be out a lot sooner.
Takahiro Amano, who is apparently an employee at peripheral company KeysFactory, has tweeted:
"On November 20, eleven 3DS products that we designed will go on sale all at once. People who are buying the 3DS, buy it at the same time! There will be more details on our home page." He then provided a link.
Nintendo is planning on making the portable's release date public on September 29. It is perhaps worth nothing that Microsoft is releasing the Kinect on November 20 in Japan and that until Nintendo reveals the release date publicly, it is possible that it could change.
While November 20 does seem soon (much sooner than Nintendo of America's "next year" claim), the day is a Saturday. Let's see how it stacks up against recent Nintendo release dates for Japan. The Nintendo DS XL was released on November 21, 2009. That was a Saturday. The Nintendo DSi was released on November 1, 2008. That was a Saturday. The Nintendo Wii was released on December 2, 2006. That was a Saturday.
There are some anomalies. The Nintendo DS was released December 2, 2004 in Japan. That was a Thursday. The Nintendo DS Lite was released on March 2, 2006. That also was a Thursday.
Amano's Twitter page has since been deleted as has his original tweet. (At the time of posting, it is still possible to view his Tweetlog.) Random tweets are certainly not viable sources of information.
KeysFactory, however, has designed a slew of DS, DSi, and DS XL peripherals, so there could be something to Amano's tweet. That is, if Amano is exactly a KeysFactory employee. On his Tweetlog, he claims to be based in Shizuoka, which is where KeysFactory is located.
Kotaku is following up with both KeysFactory and Nintendo and will update if either comments.
Update: A spokesperson for KeysFactory has told Kotaku that Amano was an employee, but left the company at the end of August. What's more, the spokesperson added that the company has not been informed of the Nintendo 3DS's release date.