Alright! after reading every single post in this thread, I'm ready to put in my two (or million) cents:
I've been taking a look at scenes during the explanation of the "Lost in Thoughts, All Alone" music, where it was easy to not notice the fact that Corrin gameplay was playing in the background.
Here's the entire broadcast (should be bookmarked at the indicated section, 6:47)
First thing to notice is at 7:04, where we get to see a FULLY charged neutral-B. It appears to charge fully in ~1/2 of a second, travel twice as fast as a fully charged ZSS blaster shot, and stuns Ryu for what seems like more than enough time to follow up. Also, the hitbox looks huge! I smell a neutral game, baby!
Next big thing to notice is at 6:58 where on the left side, the male Corrin uses a forward-kick out of side-B, which apparently seems to autocancel. Does this perhaps imply that the kick out of side-B can ledge cancel, or is it only because he falls down from the platform? Could this potentially lead to gimmicky but awesome combos?
Also, something about side-B that makes me curious is: what happens if you spot-dodge Corrin's side-B? After the spot dodge animation, will the character be pushed away due to unit collision?
Last thing that I think is extremely important yet not discussed enough here is whether or not Corrin's dragon-lance attacks will be disjointed. On one end, mentioned earlier, Corrin appears to be invulnerable to Roy's counter. On the other hand, the lances are still technically part of his body, so would a disjoin not make sense?
I feel like this question is extremely important, because if the moves aren't disjointed, then a potential counter to f-smash could be short hopping over it into Dair.
I am so ready for Corrin. Discuss!..?
EDIT:
I also noticed that in the actual trailer (1:44), Corrin counters forward smashes from Lucina and Roy, coming from opposite directions. Notice how both of them enter a laggy clashing animation after attempting to hit Corrin while in his counter stance. There could be two possibilities explaining this:
1. Roy and Lucina simply clashed with each other, while passing through Corrin.
2. Corrin's counter could cause a clashing animation on the attacker from certain moves, greatly increasing the usability of the counter. Notice how at 1/4 speed, Roy's blade actually stops first, and afterwards, Lucina's blade leaves first.