A few random thoughts:
1. Some of the Final Smashes have not been changed, including but not limited to Mario, Fox, Bowser, and Donkey Kong. I never liked Bowser's because he has way too much history to just transform into a character Sakurai invented for Melee. I was really hoping he would get the Koopa Clown Car and you could fly around and drop Mecha-Koopas or those giant marbles. Donkey Kong's is similarly terrible. Give him Rambi. It's just so weird that they went out of their way to give Kirby and Luigi new Final Smashes, but kept others the same. Not that I use the Smash Ball terribly often, but go HAM or go home.
2. Toon Link is still a missed opportunity. He also still has the same Final Smash as regular Link. Boo/hiss. It makes the Final Smashes seems less special when some characters have the same one. It also feels lazy for a game that isn't for the most part.
3. One discussion video I watched mentioned that the games play closer to Brawl than Melee. This is mildly disconcerting as I find myself disliking Brawl more and more as the years go by. However, the removal of random tripping will help considerably.
4. I still think the 3DS version will negatively affect the Wii U version, but no where near as badly as New Super Mario Bros. 2 did to New Super Mario Bros. U. First, due to the kind of game Super Smash Bros. is, it's just better suited on a TV. Additionally, it's probably far easier for most people to gather a few friends to play on a single console than find a few people who each have a 3DS and the game. Second, I keep reading that the controls on the 3DS version are serviceable though ultimately far worse than the Wii U version, primarily due to the lack of options and the Circle Pad.
5. Speaking of the 3DS version, with Bayonetta 2 coming out a couple weeks later, I'm strongly leaning toward just waiting for a Buy 2 Get 1 Free sale that typically show up around October and November. Hyrule Warriors would be my third game.
6. On Monday's Miiverse Update, Link got a Skyward Sword-inspired non-costume. He's still in the tunic but it has the design of what Link wears prior to getting the tunic. Despite all the hints and hype over alternate costumes, this points to some characters not getting one. Boo/hiss. Again, it just feels lazy for a game that goes all-out in so many different ways. Still, it's not a huge deal, just mildly disappointing. If this and some of the Final Smashes are the worst I can say about the game, it's in very good shape.