Wednesday January 9 Prediction:
I predict that Sheik will be revealed.
The more I think about it the more I wonder why it has not yet been revealed that Zelda transforms, if in fact she still does. I think that she may have lost that ability or that they want the redesigned, Twighlight Princessed up version of Sheik to be a surprise... which may mean that it could end up being something like Midna, imp or humanoid, or something even more interesting... which could also wind up being a big disappointment.
What is funny is that I do not even play as Zelda/Sheik; I just really want to see how they change the character around, if at all, because I found the transformation idea awesome in Melee.