Nintendo customer service representative David Marshall has revealed Nintendo's plans to implement a "unified account system" for the Wii U and the 3DS.
"A unified account system will be implemented later this year with the launch of the Wii U. Eventually this same account system will be made compatible with Nintendo 3DS systems," he wrote in an email, which was later reported on by Nintendo World Report.
However, Marshall was not forthcoming with information on how the system will work outside of the US and Canada, but said, "In the meantime, if the system has a problem, taking it to an Authorised 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."
This new system will possibly allow players to swap content between the consoles and may allow full downloads to be played across both devices.