Takahashi's stated reason for choosing this style and Saito as the Lead Character Designer is he felt that his style of characters lent themselves well to being very expressive in their facial features, which is something he wanted to really show off and accomplish because as you know, past games' expressions (especially X) were very plastic-doll like.
http://nintendoeverything.com/takah...ation-than-x-no-multiplayer-side-quests-more/
It's been a long time of course so my memory is hazy. I'm not sure if Marketing did anything "special" for Wind Waker aside from the usual showing it off at trade events and previews. And through that over time people started to realize this was going to be a good Zelda game, and of course by the time it launched the critics praised it, many changed their tune.
Zelda's gameplay is easier to market though. Xenoblade's gameplay, is just honestly not exciting to watch. I'm being honest there, I don't enjoy watching the battles (if I've watched lets plays of both predecessors I've always skipped through the actual battles), but I do enjoy playing them, it is a big difference IMO.
Opinion will change if more previews/reviews are positive. There hasn't been any "negative" previews to my knowledge, but then again, that is admittedly due to the way Nintendo has gone about things thus far.