This is going better than expected, though this seems to in large part due to users giving ratings quite a bit higher than their actual reasoning suggests.
Toon Zelda/Tetra - 25%
Here's a real oddity: a newcomer who depends pretty heavily on a clone character returning, and a very specific pairing that may not happen even if Toon Zelda or Tetra is included. We know that Tetra has appeared in two games now and will soon appear in Wind Waker HD, while Toon Zelda has appeared in a handful more thanks to the prevalence of the Toon universe in Zelda games of the past decade. Considering how odd being a recurring character in the Zelda games is, that's a pretty big leg up on the competition. Further, with Toon Link already being in and quite popular, the door is certainly open for more Toon characters to appear. The competition is pretty weak thanks to most candidates being one-offs or having less popularity, and being in the Forbidden Seven means she has been considered in the past (considering Toon Sheik as likely to turn to Tetra due to lack of a Toon Sheik in the games). It also doesn't hurt that Toon Zelda would likely be a Zelda clone, so only Tetra would require a completely new moveset (which she has plenty of potential for).
Really, the big problem with her is that first sentence: she's very unlikely to show unless Toon Link is already in, and even then we may just get Tetra or Toon Zelda or even Toon Zelda/Toon Sheik. There's also no guarantee the Zelda franchise will get a fifth character slot, or that she would beat out the plethora of other candidates for said fifth slot. As such, it's difficult to rate Toon Zelda/Tetra too highly. However, I feel that the pairing is still quite a bit more likely than most, and it seems the logical choice should Sakurai consider using either Toon Zelda or Tetra, thus 25% feels about right.
Want - 90% - I love the toon universe, and Tetra would surely use a unique moveset. Would be a very exciting addition.
Dillon Prediction - 35%
He's got a decent amount going for him, and I think a lot of users here know it.
Nominations
R.O.B. x5