Overall it's a mixed bag for me, but overall I'm neutral, and will have to say that my real opinion over the roster can wait until the full one is shown.
Probably the only newcomer that has been shown so far that I really care for is Villager. Villager was one of my picks in the end for Brawl, Animal Crossing has always been one of my favorite series (since it came out, that is lol), and Villager looks like a fun, unique character.
Little Mac is probably second for me. He comes from a series I have never played, but he looks like a fun character.
I can be excited for others with Mega Man, although I've never been into that series. The rest of the newcomers shown so far (Rosalina, Wii Fit Trainer, and Greninja) I could really do without, and they are the wildcards for my final opinion of the roster. If it comes out to be a small roster with more characters like them, they will be detrimental. However, if the roster comes out better in the end, then I can just let it go. But I have a nagging feeling they will be big wasted spots in the end, in my mind.