It's often easy to think of the DS as like the weird kid in school (well, aside from the fact that it's insanely popular). Similar to the shunned student, it follows its own path instead of doing what everyone else has done. While all the other formats are playing the same Lego Indiana Jones game and simply incorporating their own controls, the DS version is a different game based around the same stories.
So, if you've completed it on Wii, PS3, 360 or whatever, you need not necessarily avoid this game, especially if you want to get in as much Lego action as you possibly can. Admittedly, you would have already played the superior version, from both a graphical and game-play standpoint, but hey, a fan is a fan.