A surprise to many, Nintendo has announced a new handheld publicly before E3 or Tokyo Game Show. The new system, called the "3DS", is the true successor to the DS and will incorporate 3D technology (Avatar style) without the need for glasses. There aren't many details yet, but it will surely be interesting to see how it works and whether it will be for one screen or both. All DS and DSi software will be backwards compatible with the 3DS.
There are unconfirmed details from two Japanese newspapers (Asahi and Nikkei) revealing that the 3DS will incorporate 3D analog sticks, better wifi, increased battery life and even a vibration function. Apparently the two screens measure at four inches diagonally each. That's larger than on a DSi, but smaller than the DSi XL. These will be parallax barrier LCD screens from Sharp. The increased battery life may be attributed to LED lighting used in these screens, which are much more power efficient.
A fully working unit will be playable this year at E3 and is expected to go on sale in Japan before March 2011. All details will be revealed then.