There is an article on the Disney Parks Blog about SotMK (here).
In the article they have this to say about the last 10 cards:
Ugh! Why can't they just tell us now... But at least we'll finally get some "official" info about the last 10 cards. Just a few more weeks...The last 10 cards in the set – the Super Rare 10 – will be revealed in a few more weeks! Keep watching the Disney Parks Blog.
And one last thing...did anyone notice that the Thumper Card is different?