On November 20, the DS will get a TV-tuner (WanSeg TV Tuner DS) in Japan. This TV-tuner will only work in Japan since it use the 1seg technology, which is a mobile terrestrial digital audio/video and data broadcasting service in Japan.
The 1seg use a resolution of 320 x 240 pixels, but will only be displayed with 256 x 192 since that’s the DS resolution.
If you live in Japan, you can now pre-order the TV-tuner from Play-Asia.com.
If you read Japanese, you can go to Nintendo.co.jp for more info on the TV-tuner.