Nintendo revealed the plan to go with cartridges over CDs.
It was once a popular method in the past of running and containing video games all the way back in the Atari days, and still used for Nintendo 3DS and PlayStation Vita games. This changed to CDs we use now for many reasons, such as storage space and low costs. However, this too has changed, with companies such as Samsung Electronics Co. and Toshiba Corp., as they have developed memory cards capable of packing a lot of data in small products.
Industry watchers have stated how reasonable the choice was, given Nintendo’s wider reach over consumers when compared to Sony or Microsoft. This includes children, who would likely scratch discs and damage them. In addition, cartridges would allow games to load faster, harder to make copies, and even faster to produce. And given the portability of the NX, a disc would be more likely to get damaged inside of a console; speaking from experience for that.
Thus far, there are no updates as to what the cartridges would look like, or if the system would take 3DS games too.
