@Ao:
gotta agree with this, too. although, i'd check out my favorite arcs just to see the difference between the dub and the original. and definitely arcs centering around the dub actors i enjoy more than the ones who grate my ears; if it was airing dubbed.
If we are talking about american tv here, what are the actual chances that it will be in Japanese language?
When a kid is switching channels and find's One Piece on Nick and hear's it in Japanese, do you really think he is going to watch the show? No. He is just going to find it weird and then on Monday when school time comes he is going to make fun of it with all his friends.
So I'd say, just go with the dub. It is not like it is inaccurate at all. So that way if it did get new fans, they'd get the same feeling as watching the Japanese version!