Tier lists are fun. EVO will be a really strong data point; here's where I'm at with 1.0.8/1.0.9 pre-EVO:
Top (1-9):
High (10-22):
Mid ( 23-34):
Low (35-45):
Bottom (46-54):
Rock Bottom (55):
Notes:
-This assumes customs legal. If customs are banned, many characters drop but especially Rosalina, Palutena, Marth, Bowser Jr., Donkey Kong, Lucina, Ike, Wii Fit Trainer, Ganondorf, and Duck Hunt. I don't play the customs banned game though so other than "worse balance" I can't really supply a tier list for it.
-Patches played a VERY big role in where characters fell. Marth especially I think rockets up the tier list after the patches that helped him so much, but patches had a large impact on where most characters fell.
-My top tier is weird I know, but people really sleep on both Ness and Yoshi. They have as far as I can tell the best typical damage output of any characters, the best speed to power ratios in the cast, solid movement, and generally deep toolsets. They don't fit classic archetypes of top characters in smash games and aren't as popular in the meta as some others, but neither of those things really concern me at all.
-I'm VERY uncertain about Ryu's placement. He seems pretty bad since his anti-camp options seem not to exist which probably gives him way too many hard counters to deal with, but the upside on this character is massive too. I could be the whole tier list wrong about him, and we won't know for months most likely. For now, I'm assuming he's bad until he proves otherwise, and proving otherwise will mostly come down to showing himself to have a far superior neutral game to what he appears to have at first blush.
-In general I was very harsh on characters who I feel have a lot of bad match-ups. If I were looking at "general utility", Pac-Man, Little Mac, Duck Hunt, and Shulk would all be placed much higher, but I held match-up based downside (including stage match-ups Little Mac!) very strongly against characters since, honestly, there are too many good characters in this game to be very tolerant of poor MU spreads.
-I think the top two tiers are solid mains for competitive play, mid tier is fully viable but may be best served to work alongside secondaries or may just plain have to work discernible harder than the higher tiers, low tier is competitively usable but niche and thus only suitable for extremely dedicated players, and both bottom and rock bottom tiers are recommended against as I don't feel the downsides of these characters are sufficiently offset by upsides (though many of the bottom characters do have contexts in which they can perform well). I think this game is impressively well balanced, and when I put a character at like 30th, it's not because I think they're bad just that I think there are so many who are even better.
Like all tier lists, this is kinda just for fun, but it does reflect my current understanding of the balance of the game. I'll be at EVO and will be observing everything I see very carefully, and my list very well may change within the next week. I can probably explain what I'm thinking with most characters if asked.