Touch Screen:
The lower screen will offer something never before provided by any game device: PDA-like touch capabilities. Players no longer have to rely on just buttons to move characters or shift perspectives. They can navigate menus or access inventory items simply by touching the screen with stylus or fingertip. A software-based keyboard might even allow the screen to be used as an input center for games and messaging. The possibilities are limited only by developers' imaginations. The screen will have a tougher film cover for durability, and will come with a stylus.
Microphone:
An available microphone port means that in the future, players might need only to tell their games what to do. DS software could identify everything from voice commands to hand-clapping. Players might be able to move their characters simply by telling them which way to go. The voice capabilities also could allow gamers to chat with one another over the Internet while playing.

Wireless:
DS users will be able to connect with a local wireless network of up to 16 players. Nintendo's guaranteed range is 30 feet, but will extend far beyond that depending on circumstances. It assures high response rates required for real time game play, and will make use of both IEEE 802.11 and Nintendo's proprietary communication protocol, which provides low battery consumption. Players will be able to chat and play games without any connecting cords, completely untethered. The DS technology also provides for a wireless LAN connection, which could allow a theoretically infinite number of players to connect at a hot spot and compete at a central game hub on the Internet, even if they're thousands of miles apart.

Wireless Game Sharing:
If software developers desire, multiple players can compete in wireless games, even if only one person has a game card inserted. Players could also test-play games for themselves as long as they stayed connected.

3-D:
With the newly developed graphics engine, DS can reproduce impressive 3-D renderings that can surpass images displayed on the Nintendo® 64. Games will run at 60 frames per second, and allow details like fog effects and cel shading.

Sound:
The 16-channel sound allows for greatly expanded use of voices and music, and a richer, more immersive game experience. A plug for headphones transmits stereo sound.

Battery & Power Management:
The battery is rechargeable and the unit features a low-energy-consumption design. The DS also has Power Management functions of Sleep mode and Standby mode. In Sleep mode, players can stop and resume game play whenever they like. If the user receives a message from a friend or user nearby, DS activates itself from Standby mode.

Processing: The unit will run on two processors, one ARM9 one ARM7.

New Media: For its compact cards, the unit uses newly developed semiconductor memory, which allows for
lower cost, shorter manufacturing time and memory capacity of more than one gigabit of information.

Dual Slots: Nintendo DS makes a vast library of Game Boy® Advance games readily available. Developers could find ways to make new connections between GBA games and DS games. The GBA port could be used for new hardware, enormously expanding the functional expandability of the DS.
Info by Nintendo