I want Skull Kid back. That entire game was more inventive than any other Zelda title, with the possible exclusion of WW. Hopefully at E3 we'll hear something about the new Zelda. As far as continuity goes, we don't know the average lifespan of a skull kid, so the Skull Kid could have survived into the TP era if they deem it necessary. Brawl can draw from characters going backward, or boost them going forward. Not that I don't like Vaati--it's just that his games don't fit as well into the general timeline.
But Tingle, I sincerely believe, has a better shot than either. The only thing holding him back is the Balloon Fighter, which contends for the "Balloon-based" spot on the roster. Here's to that 8-bit hero. Japan, you frighten me.