Kyoto-based game maker Nintendo has announced a list of first party DS games for Japan, the United States and Europe. These are most likely not all the upcoming Nintendo DS games, so do keep that in mind.
Japan
Mario & Sonic At the Olympic Winter Games 2009/11/19
The Legend of Zelda: Spirit Tracks 2009/12/23
Famicom Wars DS2(Temp.) 2009
Golden Sun DS(Temp.) TBA
The United States
Pokémon Mystery Dungeon: Explorers of Sky 2009/10/12
Style Savvy 2009/11/2
The Legend of Zelda: Spirit Tracks 2009/12/7
Pokémon HeartGold Version 2010 Spring
Pokémon SoulSilver Version 2010 Spring
Glory of Heracles 2010
Golden Sun DS(Temp.) 2010
WarioWare D.I.Y. TBA
Picross 3D TBA
Europe
Mario & Luigi: Bowser's Inside Story 2009/10/9
Nintendo presents: Style Boutique 2009/10/23
Pokémon Mystery Dungeon: Explorers of Sky 2009/11/20
The Legend of Zelda: Spirit Tracks 2009/12/11
Pokémon HeartGold Version 2010 Spring
Pokémon SoulSilver Version 2010 Spring
WarioWare D.I.Y. TBA
As Nintendo points out, launch dates and titles are subject to change.