I got some news from a legitimate source, my uncle works at Gamefreak as part of their Hispanic exchange program and learned all about the new Pokemon games.
MASSIVE SPOILERS*
Froakie evolves into a turtle. I know it's a frog, but frogs are reptiles and turtles are reptiles, so it's all the same thing. It also becomes a ninja with a bandanna that will randomly be one of four colors: Blue, red, orange, and purple. Its typing will be Water/Ninja, and it will be an example of the previously unrevealed Ninja type. Froakie3 has two signature moves: Sushi Katana and Pizza Cutter.
After a rather svelte second evolution, Fennekin3 gains about 400 pounds and becomes a sumo wrestler-themed Fire/Fighting Pokemon. In addition to inheriting the Tepig line's signature move "Heat Crash", it also learns the Fighting move "Hundred Hand Slap," which is a multi-hitting move in which each hit does 5 damage; you can get more hits out if you rapidly press the A button.
Chespin doesn't evolve. It's an experiment with the very first non-evolving starter. To compensate, Chespin's Mega Evolution (Yes, it has a Mega Evolution) will make it become a much better Grass Pokemon like Breloom or Venusaur. Sorry Chespin fans, looks like you're out in the cold. I'll be enjoying my sumo wrestler fox very much, thank you.
*None of the above are actually spoilers.