It's good on Wii. Though as most will know, the IR of the Wii Remote isn't at its very best when used for drawing. It works, though, and it's quite a challenge. It will frequently have you feel pretty darn smart for solving problems in new ways.
I think the game could be even more fun on DS with stylus control. Plus, they can go from a 40MB limit to 400MB or more, so maybe there will be some surprises in there, to go along with a supposedly higher retail price.