Johnny Depp as the Mad Hatter (who else?), Helena Bonham Carter as the Red Queen, and Anne Hathaway as the White Queen.
The cast also includes Mia Wasikowska (In Treatment) as Alice, plus Crispin Glover as The Knave of Hearts, Stephen Fry as The Cheshire Cat, Michael Sheen as The White Rabbit, Alan Rickman as The Caterpillar, Timothy Spall as The Bloodhound, and more.
It's set to hits theaters on March 5th 2010. Uh, just how am I going to wait that long?!
You should also hop on over (pun intended) to USA Today, they have three interactive pieces of concept art for the film like the one pictured below.