This Alice, like most of Burton's adaptations, uses the source material loosely. The Alice in question is all grown up now, and about to be proposed to by an obsequious chinless nitwit. But then there's this strange white rabbit who leads her into a hole in a tree and--well, you know the rest. It turns out Wonderland is actually Underland, and the whole place has fallen into ruin under the terrible rule of the Red Queen (the deeply fabulous big-headed Helena Bonham Carter). It's Alice's destiny to get the vorpal sword and destroy the queen's Jabberwocky and (callooh! callay!) return the kingdom to Anne Hathaway.
This sampling and remixing isn't quite successful--some things seem to exist just for the sake of being referents. And it's difficult to hold tension in narrative when the whole plot depends on a character fulfilling a destiny we know they've had the entire movie. What's left is just how they do it, and in this case it's by (bander)snatching a bunch of different elements of the books, sticking them in a martini shaker for a few minutes...et voila. The vorpal blade went snicker-snack!
That said, what they do with Alice is a good model for character development, especially in fantasy. (Because--say it with me-- fantasy is all about the inner journey of the protagonist.) In the beginning we're presented with her in the ordinary world, not quite fitting in, unsure whether or not she should marry Lord NoChin. In Underland, everyone's trying to figure out if she's the "real" Alice, the girl of destiny--or just some other Alice. The Caterpillar pronounces her Hardly Alice early on, while Johnny Depp says she's the real Alice but she's "lost her muchness." Which is an awesome way of putting it. Alice can't seem to fit into her heroic destiny--she can't even stay the proper size. The movie is about her journey from Hardly Alice to the Real Alice (who, while being apt with the vorpal sword, is also a raging capitalist).
They do something very curious with this journey, too. Through Underland, Alice survives and succeeds through her basic goodness. She acquires allies because she shows them kindness--that's her power. And she wants no part of slaying the Jabberwocky; she says she couldn't possibly slay anything. So her ultimate success rides on her ability to decide that she can be a killer after all--in sense, overcome that goodness. Which makes you go, Huh.
Anyone else see it?