There is a recent One Piece game that came out for PS2/Cube. This new one has significantly better graphics. The cel-shading is more reminiscent of Wind Waker, but with more character geometry.
IMO, it looks like quite a few Japanese developers are working with a "Wii is basically like Gamecube, and Gamecube is basically like PS2" mentality. Someone had earlier mentioned something about Japanese developers essentially having half a generation to catch up on, and I think it really shows in the disparity of some of these titles. After all, this:
http://www.watch.impress.co.jp/game/docs/20060914/wiiscr42.htm
looks almost a generation ahead of this:
http://www.watch.impress.co.jp/game/docs/20060914/wiiscr19.htm
...and the first one is a Gamecube port, while the second is Wii exclusive! I think a lot of the 3rd parties haven't at all grasped what the GPUs that came between Voodoo-era rasterizers and the modern shader monsters are capable of. I expect developers who really played around with Xbox and Cube to have a massive graphical head start over the likes of Koei, Bandai, and other Japanese developers who focused all their attention on PS2.