This info comes from the same source that accurately detailed the most recent Pokemon X/Y Pokemon reveal.
Pancham evolves into Pangoro in the early level 30s. In order to evolve Pancham into Pangoro, you need to have one other Dark-type Pokemon in your party. Pangoro's type is Fighting/Dark.
A Pokemon named Inkay evolves into Malimar. To evolve it, you have to hold your 3DS upside-down when it levels up (the 3DS has an accelerometer and gyroscope, so it can detect that). Malimar's type is Dark/Psychic.
A Psychic-type Pokemon named Espurr (ESP + purr) evolves into Meowstick (Meow + mystic?). (Sounds like Psychic-type cats. Meowstick's name sounds too similar to Meowth to me though.)
Like in B/W you have two rivals - one is friendly and the other is competitive. Your rival that is more friendly gives you his/her fully evolved starter Pokemon after you beat the game.
Another professor named Sycamore gives you either Bulbasaur, Charmander, or Squirtle.
Even though it shows the player riding on a Gogoat in the new trailer, players can't ride on their own Pokemon. What was shown is just an alternate way of getting around Lumiose City and it only works with Gogoat.
HMs still exist but there's a lot less of them.
Players will be able to see their Pokemon's EVs (probably through the same in-game facility mentioned in the other post).
A new move, Belch, is a Poison-type attack that has a base power of 120. The user must consume a held Berry to perform it.
Draining Kiss is a Fairy-type attack that heals the user for the same amount of damage performed. It has a base power of 60.
If the previously revealed forme of Mewtwo can be said to look roughly similar to Mewtwo's original design, the second supposed form of Mewtwo can be said to look roughly/vaguely similar to Mew's design.
In case you missed our correction the other day, the Starters' final evolutions are Fire/Psychic, Grass/Dark, and Water/Fighting.