Well it's been quite a while since I've actually played this game (and subsequently updated the first post). I missed a couple Weekend Challenges over the holidays, so I'll have to work to get my tickets. Also, the Holiday pay for pack left a bad taste in my mouth. I don't mind if the fact that one COULD pay for characters, but when it's the only way to unlock characters, it doesn't jive well with me. I'm thinking this new ticket machine will allow users to unlock such characters without paying them. If that's true, it's a good move.
First post has been updated with the Weekend Challenge characters I missed as well as the secret characters in Mulan. I don't think all have been found yet, so there will be more updates.