I'm loving it so far. Brawl's was awesome as is, and I think it's approaching Brawl levels of perfection.
Ignoring vets and Palutena (who I want but am sure will be in the game), it'd be perfect if:
-Snake returned (the only vet who I am uneasy about, but he is one of my favourite characters)
-Professor Layton was added
-Some obscure character I don't know anything about is added that has a very unique moveset, and possibly gets me interested in their origins (Pit was this in Brawl - bonus points if they get a game)
And it will be beyond perfect if Reggie Fils-Aime/Reggie Fils-A-Mech is in it.
In terms of what we already have, I'm satisfied. I was really happy to see Sonic confirmed to return, and the prospect of him being a possible constant in the series makes me happy. Mega Man and Rosalina, especially Rosalina, were two characters I was dying to see in Smash (and I could write an essay on how Rosalina excited me and how I think she more than deserved it, I've wanted her since the Brawl days - I was also kinda worried she'd only make Assist Trophy since it's rumoured she was intended to be one in Brawl, but was replaced by Gardevoir as a Pokémon). Little Mac is not one I personally was attached to, but had an interest in seeing in the game, and I'm really happy with how they handled his moveset (and his trailer, his trailer was great). Villager and Wii Fit Trainer are fun and quirky additions, and a good reminder that not every character has to be serious, old, or a badass. Greninja is one I am indifferent too. He didn't excite me, and he seems to be the least interesting one moveset wise so far. I'm fine with him being there, though I think he would have made more sense as a hidden character, rather than announcing him at the end of the Smash Direct.