"Nintendo announced the 2DS on August 28th 2013, a new entry-level handheld system. The 2DS will be available for $129.99 on October 12th and features a slate-like design rather than the clamshell seen on DS and 3DS models.

The 2DS is fully compatible with all 3DS and DS games but does not include the ability to display games in 3D. It still features all the functionality of 3DS (WiFi, local multiplayer, etc.) and can be put to sleep using a slider that replicates closing the clamshell on a standard 3DS. WiFi can still be turned off, though it’s done via controls in the software rather than with a physical switch.

The 2DS will launch in red and blue models to start and will be sold alongside the standard 3DS and 3DS XL. It will include a 4GB SD card and uses the same power source as 3DS and DSi. It also includes two cameras on the reverse side, so AR games still function and players can still take 3D photos -- they simply cannot be displayed on the 2DS, but are still viewable in full 3D if transferred to a 3DS. The 2DS only includes one speaker, which plays mono sound, but features full stereo via its headphone jack.

According to Nintendo of America president Reggie Fils-Aime, the idea for the 2DS came from wanting to appeal to younger consumers, as the standard 3DS is aimed at players age seven and up."

Source: Wikipedia, "Nintendo 3DS", available under the CC-BY-SA License.