The DS isn't exactly known as the place to go for arcade-style versus fighters, but with the system still topping the hardware sales charts, you just knew that was gonna change. And it has.

At the recent MMBB Online Game Festa, a King of fighters tournament and demo event held by Online service provider KDDI on 4/22 in Tokyo, KOF series producer Falcoon announced that details on a DS version of King of Fighters would be announced in the near future.
That's all the man said. For now, take this as confirmation that a DS version of the classic arcade franchise is in development, and start praying that SNK Playmore doesn't get experimental with the stylus.

http://uk.ds.ign.com/articles/702/702928p1.html