I just found out about FrockTalk.
From their site description -
Welcome to FrockTalk, the web’s only costume-based movie review site. The goal of Frocktalk is to shed light on the magnificent artistry of costume design in motion pictures. Reviews on this site are written by working costume designers in the entertainment industry – people who know, better than anyone, what it takes to make it all happen.
The focus of FrockTalk is not to comment on the big flashy costume dramas, but to call attention to the seemingly ordinary costume design work in film that silently and persuasively moves the audience toward understanding the characters. Costume design for motion pictures is an art form that deserves more recognition than it usually gets. Fancy, pretty costumes do not always equal effective, appropriate costumes. The art of the costume is in letting the audience know who the character is, before the actor even has a chance to open his mouth. Read on, and enjoy.
The May 29th entry is about "Snow White and the Huntsman" costumes.