Not that it's going to be really useful until someone is found who can read Japanese but I've found a few videos demonstrating what was in 1.0.3, it doesn't show the changes however it only 'talks' about them.
Part1:
https://www.youtube.com/watch?v=kmCHU...
Part2:
https://www.youtube.com/watch?v=cYLns...
Part3:
https://www.youtube.com/watch?v=Bjwlz...
Part4:
https://www.youtube.com/watch?v=eUmyc...
Below is a list of the changes claimed by the video. Of course I'm not sure if any of it is accurate. A lot of it is about how there "seem" to be changes, and some of this stuff has been disproven according to this thread. Might be a good list for running tests though. Any notes I make are in [brackets].
Also, the video makes a distinction between "destructive power" and knockback. I'm assuming the former to mean "damage" and have labeled it as such, but am not entirely certain about that.
Mario
-Recovery in general has been reduced [Mainly shows air attacks]
Luigi
-Jumps and Up B go higher
-Has a quicker fastfall
Peach
-No more turnip ledge canceling
-No more ledge canceling
Bowser
-Bowsercide KOs Bowser first
Yoshi
-Yoshi's recovery on dash attack increased
-Neutral B comes out more slowly
-Up B has less range
-no more teleport
-Neutral Air comes out more slowly
-Mega Man is no longer susceptible to grab release -> Up Smash
Rosalina & Luma
-Respawn time on Luma has been increased
-Neutral B has less range, Luma moves more quickly when returning to Rosalina
-Luma can't be controlled after the opponent inputs their throw command
-Neutral Air and Up Smash have been reduced in both damage and knockback
Bowser Jr.
-Forward Smash hits better? [This doesn't quite make sense to me. It might be claiming that the Forward Smash doesn't whiff on up-close opponents as much, but when I tested it the attack missed opponents who were "inside" Bowser Jr.]
Wario
-Aerial movement bug (Wectoring) removed
Diddy Kong
-Up Air's knockback reduced, recovery increased
-No more Peanut Popgun canceling
Donkey Kong
-DK can hit opponents better when they're standing right next to him [Tested this with a Mario walking into DK, forward smash and forward tilt still don't hit, but they do hit if Mario is standing just a tiny distance away. Not sure if this is a change]
-DK's face on his down taunt has changed [If there's any change here it's really minor]
Pit
-Recovery on Down B and Side B have been reduced
Palutena
-Grab reach has been changed
-Down Tilt recovery has been reduced
-The wind on the Forward Smash has become stronger
-No more meteor on Neutral Air
Kirby
-Recovery in general has been reduced
-Dash attack and Smashes are quicker
-Repeated Down Tilt is quicker
-Reach on forward tilt is greater
King Dedede
-Less damage on Forward Air
-Gordos continue on for longer? [This one seems to not make sense. At first I thought it was claiming that Gordo's stay out for longer, but I think it's saying that Dedede takes a bit longer to act after throwing out a Gordo]
Meta Knight
-No more Meteor on Forward Air
-More damage on Smash Attacks
-Meta Knight can grab the ledge at the end of a Side B [It seems to be claiming that Meta Knight can grab the ledge right after Side B finishes, but I tested it and this isn't the case. Meta Knight can grab the ledge during Side B, but I don't know if this has always been the case]
Marth
-Up Throw into Up Air connects at low percentages
-Side B chains come out more quickly
-Quicker dash
-Forward Air reaches behind Marth
-Recovery in general has been reduced
Lucina
-Same changes as Marth's above
-Meteor hitbox on Down Air has been increased
-"Chest has gotten a bit bigger" [I don't think this is testable]
Ike
-Forward Air comes out more quickly
-Jab is quicker
-Less recovery time on Down Tilt and Forward Tilt
Robin
-Less recovery time on grab
-Quicker dash
-Dash attack has changed [Doesn't specify how]
-Can grab the ledge out of a backwards Up B
-No more Thoron jump restoration bug
Link
-No more bomb canceling
-Back Air recovery time has been reduced
-Motion and range have been changed on Link's Up Tilt and Up Smash [I can't tell any difference]
Toon Link
-No more bomb canceling
Zelda
-Down Air, Up Smash, Side Smash, and Side B all come out more quickly and have their recovery times reduced. Visual effects on these moves have changed as well.
-Longer "hit stop" [Not sure if this means hit stun or freeze frames when hitting] on Forward Air, Back Air, Down Air, and Forward Smash
Sheik
-No more Meteor on Up Air
-No more Bouncing Fish ledge canceling
-The rapid fire on Needles is slower
-Damage on Forward Air and Bouncing Fish have been reduced
Ganondorf
-Quicker dash
-Quicker [sharper?] movements in the air
Fox
-No more Meteor on Forward Air
-Recovery on Up Smash is longer
-Side B travels less distance [Looks to be the same to me]
Falco
-Recovery on Neutral B (lasers) has been reduced
-Recover on Up Tilt has been reduced
Pikachu
-Recovery on Forward Air has been reduced
-Recovery on Forward Smash has been reduced
Charizard
-Non-Special attacks in the air come out more quickly
Lucario
-More recovery time on Up B (Extremespeed)
-Damage reduced on Aura Sphere
-Damage reduced on Forward Smash
Jigglypuff
-Spinning Bug [I assume this mean the "Hyper Rollout"] has been removed
Greninja
-Greater recovery time on Water Shuriken
-Greater recovery time on Up Smash
-More damage on Down Smash, less damage on Up Smash
-Up B pushes opponents away less
Mr. Game & Watch
-Bucketing Pikachu's Thunder only fills up one slot
Zero Suit Samus
-Time stuck in Neutral B reduced, less knockback on Neutral B as well
-Easier to hit Greninja with Side Smash
-Recovery time on Forward Air reduced
Ness
-Time stuck in grab increased
-Rapid down tilt is quicker
-Down Air motion has been changed
-More "hit stop" [again, not sure if this means hit stun or freeze frames] in general
-Higher chance of down tilt tripping the opponent
ROB
-Air attacks, Down Smash come out more quickly
-Less mobility in the air
Pikmin & Olimar
-Pikmin follow Olimar better when starting the match with a dash? [The video creator seems to not be so certain about this]
-Longer range on Forward Smash
-Can no longer call back Pikmin who have been tossed off stage
Little Mac
-Neutral A has been weakened
-Less distance on Side B
Villager
-No more ledge-canceled Lloid Rockets
-Up Smash is stronger
-Something feels uncomfortable about Up Tilt
-Recovery time on air dodge increased
Wii Fit Trainer
-The back side of Forward Air no longer hits through shields
-Deep Breathing is more difficult
Shulk
-Easier to connect with both hits of Forward Smash and Up Smash. The inside of the attacks do more damage but is more even or more "Marth-like" [Honestly don't know what that second part means, might refer to the fact that the first hit doesn't send the opponent flying]
-Less time needed to wait for Monado arts to restore themselves? [The wording on this is strange]
-Something about the Down Air Meteor and complete death [I think he means it's easier to kill with it?]
-More invincibility on the Down B counterattack
-Down B's timing is stricter but the move is quicker overall
-Forward Air comes out more quickly
-Harder to pivot out of a dash [I assume this means the time it takes to go from pivot back into dash]
-Throws are stronger
-Back Air is faster
Pac-Man
-Harder to launch the hydrant, neither Back Air nor Melon can break it.
-Grab works up close [Tested this, it works. Previously it would miss if the opponent was too close to Pac-Man]
-Greater recovery on Smash Attacks
-Water bug removed [According to the video, the melon could be launched at super speed after Pac-Man walked up against the hydrant water a couple of times, as if the momentum of the water transferred to the melon]
Mega Man
-More recovery time on Slide
-Slightly less landing lag on Forward Air and Back Air
-Feels like Up Smash and Down Smash come out more quickly and have greater range
-The Up Air Tornado has gotten bigger
-No more Rush Canceling
Captain Falcon
-Up Taunt does damage [Doesn't work, as far as I can tell]