As the entire Magic rumor world anxiously awaits the possibility of end-year Born of the Gods official spoilers, the mysterious source at the MTGSalvation Rumor Mill that moderator TK-421 has dubbed the Oracle of Salvation is back with a monster of a hint that seems to point toward a certain Merfolk planeswalker in Born of the Gods:
You just never know when someone will just say something crazy to you!
For instance, I heard about this:
"It was not suprising the tritons mistook her as Thassa. After all, vaporizing her foes and exploring into the deep sea for fascinating creatures were something Thassa might do. "
For the character in question to be mistaken for Thassa, she must undoubtedly be a Merfolk; and probably not a mere legendary creature, either - only a planeswalker could really approach the power level of Theros's Gods. "Vaporizing her foes" implies some kind of creature bouncing ability, which admittedly any partly-blue 'walker might do, but the last part - "exploring into the deep sea for fascinating creatures" - is known to be the main thrust of Kiora's mission.
The main question that remains is whether we'll see a green-blue Kiora at first, or whether she'll begin as monoblue - though it's certainly due time for our first green-blue planeswalker, R&D is notoriously conservative about planeswalker design space, color included.