A new trailer for Midna has been released. It shows off some of her attacks, with and without a wolf companion, as well as some hookshot action!
As of now, each of the characters that have been previously confirmed as playable have been given at least one trailer. However, it is known that Zant and Ganondorf are both in the game, and there's still more reveals to come. The game comes out in Japan in mid-August, so we're sure to see some more reveals in the meantime.