I think that they should push the new games by adding the final forms of the X and Y starters. Each of them are different in both speed and weight. Would like to see pokemon change moved to the taunts so I'll include both sets.
Down-B: Pokemon Change
Froakie- Fast and relatively light, just like Squirtle but he will be pretty tall.
Neutral-B: Dark Pulse or Bubblebeam. Dark Pulse could be a slow projectile like Wolf's blaster in Project M. Bubblebeam could be either slow or fast.
Side-B: Water Shuriken (signature) rapid fire for like 2-3% per shuriken
Up-B: Bounce -- like D3's but maybe a little more control
Delphox- Kind of like Zelda but uses her stick/staff for attacks.
Neutral-B: Psychic -- like Mewtwo's but better range or knockback instead of stun
Side-B: Mystical Fire (signature) works kinda like Din's fire
Up-B: Fire Pledge or Flame Charge. Fire Pledge could create a pillar that boosts it upwards. Flame Charge could be like Fire Fox, but no charge up time.
Chesnaught- Big Slow and Heavy
Neutral-B: Spiky Shield (signature) Like a Shine or Kirby's stone. When in the shield it acts somewhat like the Unira item from Brawl but can be grabbed out of it.
Side-B: Needle arm -- like Ike's side-B
Up-B: Sadly it kind of has to be Vine Whip, but they could make it more like melee.
Taunt Change
Froakie
Neutral-B: BubbleBeam
Side-B: Water Shuriken
Up-B: Bounce
Down-B: Dark Pulse -- Short range projectile that goes out on both sides, or has a push effect like Ness's PSI Magnet.
Delphox
Neutral-B: Light Screen -- reflector
Side-B: Mystical Fire
Up-B: Fire Pledge or Flame Charge
Down-B: Psychic
Chesnaught
Neutral-B: Bullet Seed -- like Ivysaur, but goes in an arch and can change the angle
Side-B: Needle Arm
Up-B: Vine Whip
Down-B: Brick Break -- Grounded - fast chop that can be charged and does good shield damage. Aerial -- downward dive chop kind of like Bowser's or Yoshi's down-Bs. Looks a little like Dante's Helm Breaker from MvC3.