Nintendo has contracted the production of its Nintendo 3DS cartridges to Taiwan-based solid-state maker Macronix. And apparently, those cartridges offer enormous memory space.
According to Taiwanese-site Gamrade, the 3DS cartridge is able to hold up to 8GB, but it's rumored Nintendo will be enforcing some kind of 2GB limit on 3DS games (details are few and far between in the report), with 1GB the supposed very least required. So don't hold your breath for 8GB Nintendo 3DS games any time soon; however, that may change over the course of the console's life.
Still, this shows just how much of an improvement the 3DS is considering the biggest cartridges for the Nintendo DS are only 512MB.
Remember that this is unconfirmed, and Kotaku is following up with Nintendo. This post will be updated should the company comment.