You heard right, there is but one new DS demo at the Nintendo Channel this week. And it is Square-Enix/Taito's Arkanoid DS, which actually should prove fun.
In addition to this lone new title are all of last weeks demos including:
Pirates of the Caribbean: At World's End
Worms: Open Warfare 2
High School Musical: Makin' the Cut
The Mummy: Tomb of the Dragon Emperor
plus the 4 mainstay Nintendo demos (Brain Age 1 and 2, Flash Focus, and CrossworDS)
Also, please note that the Cake Mania 2 demo is removed, with Arkanoid DS taking its place; as to why is anyones guess.