There is a Matchups/Tier List on EventHubs you can vote on

[superange]

On EventHubs, if you have an account you can vote by going to a character then setting a score on how each matchup for that characters (5/5, 3/7, 9/1, etc.)

This is what the current tier/matchups list looks like:
http://www.eventhubs.com/tiers/ssb4/

Since many people can vote, the rankings are always changing.

You can view status on what a character's overall matchup score is. For example:
http://www.eventhubs.com/tiers/ssb4/character/robin/

While the game has only been released in America for 3 days, what do you think? Do you think it's a fairly good list so far? If you disagree that you can always cast a vote!

 

[tatsurou]

Funny how Mac has the highest amount of votes but is one of the lowest tier. Butthurt much? In order for this to be anywhere near accurate even in terms of an aggregate users should have to rank 1-48.. Right now this seems to just be a popularity contest. I'll take a look in a few months.