Nintendo will bring unified personal accounts to its online services sometime this year.
"A unified account system will be implemented later this year with the launch of the Wii U," said Nintendo customer service representative David Marshall in an e-mail response to a customer, as reported by Nintendo World Report.
"Eventually this same account system will be made compatible with Nintendo 3DS systems. At this time we have no additional details to offer and nothing to indicate how or if this will work outside the United States and Canada. In the meantime, if the system has a problem, taking it to an Authorized Service Center will maintain the Nintendo eShop account. If the system is stolen, we can transfer the account to a new system once we are provided with a valid police report."
He also confirmed that the digital format of New Super Mario Bros. 2 will be limited to United States and Canada in North America.
"Of course, you asked this question because of the upcoming launch of New Super Mario Bros. 2 in retail and digital formats. What you need to know is that the digital format will only be available in the United States and Canada. We have nothing to announce regarding Latin American availability."
New Super Mario Bros. 2 will be the first Nintendo published game to be released both online and in retail on the same day. Going forth, that will be the company's policy on all first party 3DS and Wii U titles.