The article (back from 2006) says this winter, but from what I'm understanding, it will be available for pre-order this June.
Sim City Set for DS
The original Sim goes dual screened this Winter.
by IGN Staff
August 30, 2006 - Electronic Arts may not be known for making major game announcements over in Japan, but here's one for you: Sim City DS! That's right! The original Sim is set for DS release through Electronic Arts, and the latest issue of Famitsu is home to first details.
Sim City DS is based on the PC Sim City 3000. This isn't just a port, though, as the game features full stylus-based controls, mini games and a new adviser character who helps you out when designing your city.
The DS title includes three main modes of play: Build a New City, Save the City and Sister City. In Build a New City, you start a city from scratch. Save the City mode puts you in a city located somewhere in Japan and has you clear missions involving fixing traffic and other problems. The Sisters City mode lets you chat with other players and trade "landmarks."
We're not sure why Sim City DS was announced in Famitsu, but we hope it will also see official announcement closer to home, as a stylus-based Sim game is just what the DS needs. Sim City DS is set for Winter release in Japan.
link, along with screenshots: