That "off with her head" quote is just one of the fan-pleasing moments that show up in this new trailer for Tim Burton's sequel -- let's face it, that's what it is -- to the Disney classic/Lewis Carroll book, "Alice in Wonderland." Sure, Burton's flick is also called "Alice in Wonderland," but the story is set long after the events in the original story.
You actually get a bit of that exposition in this new trailer as well, so if you're unclear on how the story is set up you should definitely check it out. Also check it out if you're already a fan, as there's a lot of great stuff here: the Red Queen (Helena Bonham Carter) shouting her famous line, her playing card army on the march, Johnny Depp's Mad Hatter being... well... mad and plenty more. No caterpillar though. Bummer.