It's said that the Academy in general votes for the craft categories in one of two ways: either it votes for the "Most" instead of the "Best", or it votes for the movie it likes the best.
If they're voting for the "Most", then I say
Alice in Wonderland will win for Colleen Atwood's colourful (see: glaring, clashy) fantasy threads, since there's no decadent 18th Century royalty porn for them to vote for.

If they're voting for whatever they like the most, then it's obviously going to
The King's Speech. Add to that the fact that, while not exactly like the royalty porn of the last four years, the film is technically about European monarchy, and thus can keep this category's streak alive. I'm venturing that Jenny Beavan will celebrate her first win in 23 years.
You could apply the same logic of a win for "Most" Costume Design to
The Tempest and Sandy Powell's interesting costumes, but that movie is despised to an extent that makes even
Alice in Wonderland look good.
I Am Love is contemporary, so it's out, and no Western has ever won, so that should nix
True Grit as well. That's not to undersell Antonella Cannarozzi and Mary Zophres' terrific work. Both of them, especially Zophres, did awesome jobs at using clothes to accentuate character, and it'd be swell to see one of them win, but keep dreaming.
Will win: The King's Speech
Runner-up: Alice in Wonderland
Should win: True Grit
Should have been nominated: Get Low