Yes there will be an MK DS. Shaun Hemmerick, the developer of Mortal Kombat Shaolin monks, is working on the title. Check this news lead for more information: click here

In the shaun Hemmerick transcript, he talks about the Nintendo DS, and also why MK for PSP hasnt been so unpopular.

"All that Shaun would hint at was that while it wasn't a direct port of a previous title, it wouldn't be a brand-new game either."

Like MKTE or GBA. It was a "Continuation" of MKDA. If im not mistaken it acualy adds a few lines to raidens intro in the beginning of the game. Not a sequel. Not a direct port. Not a new game.

I would love to see a version of MKA for DS that like that. Cut out all the filler charcaters. Leave us the fan favorites. Give the people who dont a have a wii a chance to play as khameleon. Mabey add Kia & Jataaka or something as "new" playable charcters or something.