This dress is by designer Leanne Marshall, or "Leanimal," the winner of the 5th season of Project Runway. It is brand new (I ended up going with a long dress for various reasons -- some of which included my mother and the fact that it was January), and the design is impeccable. The dress is actually two pieces: a tight Alencon lace "shirt" that goes over a sweetheart neck ivory silk shantung dress. The shirt is also ivory, and sits perfectly on top of the dress, which has a full skirt and tulle underskirt to give it a little bit of volume. The dress is edged at the bottom with just a little bit of lace.
I have listed it as a street size2, but I'd say it actually fits between a street size 2 and street size 4.
If you'd like to see more photos, they are listed on Leanne Marshall's Etsy page.