Confirmed on the Twitter and Facebook Page of N-Space (Dev Of the DS version of the Game)
though this is a double edge as rumour circulating that N-Space is about to close down... Link
No offical word on there site at the moment.
n-Space confirms the addition of Zombie mode in Call of Duty: Black Ops DS. Co-Op Commie Zombie killing goodness for 1 or 2 players via local and wifi connections! Braaaiinnnssss...
though this is a double edge as rumour circulating that N-Space is about to close down... Link
No offical word on there site at the moment.