Sienna Miller Anna Wintour The September Issue Premiere

Aww, even though Vogue editrix Anna Wintour made some harsh comments about Sienna Miller in The September Issue, (she called her "toothy," among other insults) the two looked like longtime BFFs at the NYC premiere of the documentary last night. And we never thought we'd say this, but Sienna picked out a better outfit than Miranda Priestly Anna! We're loving the shade (and the flirty length) of her strapless powder blue frock, and she looked absolutely amazing.

The September Issue follows Anna and the Vogue staff for the production of the September 2008 issue of the fashion bible, and we can't wait to see it!