Nintendo's much-anticipated 3DS gaming handheld had a stellar debut in Japan this weekend, selling close to 400,000 units in just two days while the top selling launch title Professor Layton and the Mask of Miracle moved around 120,000 copies during the same timeframe. Although stocks are reportedly dry for now, more units will inevitably arrive in the week as Nintendo tries to reach its target of 1.5 million units shipped in Japan and 4 million worldwide by March 31.

Meanwhile, it seems hackers are not wasting any time in getting homebrew software and backups running on the device. The video embedded below shows how an R4 cartridge can be used to run unauthorized DS and DSi games. Technically this is just an extension of an existing DS hack onto the 3DS, and so far it doesn't apply to newer 3DS titles, but it might give Nintendo a reason to worry after spending considerable time and effort to ensure its latest handheld is unhackable, and even claiming the 3DS's technology will dramatically mitigate piracy efforts on the 3DS.

Europe is scheduled to receive the highly anticipated Nintendo 3DS beginning March 25, while the official launch date for the U.S. market is set 2 days later on the 27th priced at $250. The company also recently confirmed that the 3DS will be backed by 18 games on U.S. launch day, with plans to have some 30 titles available by early June.