I am not sure the DS market can sustain many more million sellers (other than Pokemon). Here are a few examples:
The new Kingdom Hearts game has had a dreadful start in Japan.
Also, the new Professor Layton game isn't selling very well in NA. Someone above also provided Final Fantasy IV as an example of a poor selling DS game that should be performing better.
If these games can't sell that well, I have a less than optimistic outlook on games like Okamiden and Super Scribblenauts.
I love the DS, but their momentum is currently hijacked by Apple, the impending 3DS, piracy, and a recession.
Most anticipated games of 2011:
Uncharted 3,Legend of Zelda: Skyward Sword, Rocksmith
Modern Warfare 3, Super Mario 3D