No, I have the Blue Pikmin and the Light Sabers. In fact, I have all the hacked items. I'm actually great friends with the creator of hacked items.
No, the only way for it to do anything is if Nintendo creates a DLC item using the same coding as the hacked DLC item, and what would happen is that the hacked DLC item would be overwrited by Nintendo's. Or your Wii could get bricked (1/1000 chance happening). Really, no worry at all.
