I think the dress (Oscar de la Renta) would be fabulous on someone with more of a romantic/free-spirit nature, but with Emma Watson's gamine haircut and love of all things tailored and neat (she was the face of Burberry after all), this dress wears her a little? Perhaps she should donate it to A Cardigan Girl, mmyes???
Okay, I should perhaps have read the blogosphere a little more thoroughly. She actually wore the dress with this super chic Antonio Berardi jacket, which I think you'll agree, is much more Brit style/Emma Watson.
This works much better, doesn't it? It's curious that something as simple as a plain white blazer should change an outfit to that extent, but it really balances out the wild tulle, and moves the outfit towards EW's gamine personality.