Apparently, said 3DS iteration will be launching in March in Japan, and Nintendo is planning on micro-transaction-ing the crap out of it. It's said that Nintendo has already updated the 3DS's firmware to allow this to work, letting gamers use pre-paid cards or credit cards to make in-game transactions. While this will only be available to Nintendo at first, a third-party roll-out is expected soon after, coming in as soon as the Summer of 2012.
This tech will also carry over to the Wii-U, allowing developers the ability to add paid DLC to their games when the system launches in the second half of 2012. It's expected that Nintendo will elaborate on this during its streaming press conference later today, so be sure to check back for more information.