Personally, I would say it was. I, personally, wouldn't mind if the next Zelda game was very similar to it. The only real problems I had with it was the lack of dungeons (2 to be precise, god dammit) and how the islands were so small. I also thought the graphic style was very fitting to the game, but that is for another topic. Of course, I would get a bit bored of the sailing if it was the same in the next Zelda game. A little less sailing would be great. But I liked the sense of adventure I got from sailing. It's just that I got such little reward from them. They were just little chunks of land, really.
So, would you say that the Legend of Zelda: The Windwaker was a step in the right direction for Zelda?