I'm guessing Rayquaza will move in a motion reminiscent of its animation in Pokemon Battle Revolution, or move in a "infinity" motion (as in, it will snake its way around in the air in the motion of a sideways 8) These ones seem implausible, though...
I hope Charizard roars upward, like its upward taunt in Super Smash Bros. Brawl...
I'm wondering if fainting or status animations will be present as well? IMO, this would sort of be unnecessary, but major props to the spriters if they make this happen. i know reusing HGSS sprites will be a huge help to them, but I hope some of the old ones get altered to either DP or Pt sprites instead (like Lucario and Rampardos)