Anna Wintour, the formidable editor of Vogue (and the rumored inspiration for Miranda Priestly), was not invited to the premiere. She did however attend an advance screening for the press (dressed, head-to-toe, in Prada.)
Emily Blunt was cast before Anne Hathaway. In several scenes, she is seen running about in the background - though never written or directed, she felt her character would always be busy and wanted to keep her alive in the film. Also, most of her wardrobe is from Vivienne Westwood.
Anna Wintour, the powerful Vogue editor on whom Streep's character was widely believed to be based in the novel (Weisberger once worked as her assistant), reportedly warned major fashion designers who had been invited to make cameo appearances as themselves in the film that they would be banished from the magazine's pages if they did so. Wintour's spokespeople deny this claim; however, it is notable that Vogue and other major women's and fashion magazines have avoided reviewing or even mentioning the book in their pages.
The film makes quite a few changes to the book. In the novel, Miranda's tyrannical nature is more obvious. In the film, they decided to tone her character down. She's still as domineering, but they thought it would be funnier if Miranda remained calm while making impossible demands. Nigel is only a minor character in the book and a flamboyantly gay stereotype. His role is expanded in the film, and while he is probably gay, Stanley Tucci's portrayal of it is a little more subtle (glancing at men at a fashion shoot). Also in the novel, Miranda is British and Emily is American. In the film, they're swapped around. Emily Blunt insisted Emily should be British. Finally, Lily's accident in the book becomes Emily's. Lily becomes an alcoholic after watching the effect Runway has on Andy, but instead of being hit by a taxi like Emily, she drives into one in the book.
On the first day of filming, Meryl Streep told Anne Hathaway "I think you're perfect for the role. I'm so happy we're going to be working together." Then she paused and followed it up with "That's the last nice thing I'll say to you." And it was.
In 2013, Lauren Weisberger published a sequel to the first novel, Revenge Wears Prada. Its set ten years after the first, where Andy Sachs is the editor of a wedding magazine and engaged to a man called Max; she later has a daughter with him, called Clementine Rose. Emily Charleton works with her now. Andy and Emily saw each other at a cooking class after Emily got fired from Runway for no reason; Emily eats more since the sacking. She went to work at Harper's Bazaar as a junior fashion editor. Andy and Emily became best friends and set up their own magazine together. Emily has since taken up smoking and Andy does sometimes as well. Emily is now married to a man called Miles. Andy never got back together with Alex (Nate in the film) after seeing each other for six years. He took a teaching job in the Mississippi Delta (he became a chef in the film). Andy and Lily renewed their friendship but Lily moved across the country to Colorado. She had spent a month in rehab and wanted to move because New York had too many bad memories. Lily decided to teach an undergraduate class at UC Boulder. Lily marries and becomes a mother. Andy and Lily used to do everything together, e.g. prom nights; volunteering at Avon's no-kill shelter; cross-country; state fairs; drinking, etc. Nigel and Serena appear too, not pleased that Andy never said goodbye to them. Nigel is getting married to someone called Neil. Alex (Nate) turns up and Andy realizes how much she's missed him. Andy hasn't set foot in a Starbucks since she left Runway. Miranda has gotten remarried. Emily was Miranda's head assistant for two and half years. Miranda doesn't remember either of them, since she's had several assistants since they left. Her latest assistant is called Charla, and she's terrified of interrupting Miranda at home. Andy has never read Runway since she quit. Miranda wants to acquire a magazine called Plunge, something Andy doesn't relish because it would mean working for Miranda again; Emily however loves the idea and reacquires all of her bad habits. Andy admits that Miranda still haunts her ten years on, and has started writing a tell-all book about what it was like working for Miranda Priestly; The Devil Wears Prada was a thinly veiled account of Lauren Weisberger's time at Vogue working for Anna Wintour. Emily has started wearing glasses. She gets a job as stylist to the stars in LA; her clients include Sofía Vergara; Stacy Keibler; Kristen Wiig; Carey Mulligan, etc. The book's ending hints at a reconciliation between Andy and Alex/Nate.
The book that Miranda asks Andy to retrieve for her twin daughters is Harry Potter Book 7. One of the prop books used in the movie sold in an on line auction for $586.00 and proceeds went to Dress for Success, a non-profit organization that assists more than 45,000 disadvantaged women each year as they transition into the workforce.
A 'Runway' issue is displayed behind Emily's desk, next to the fax machine. It features a cover with three models. It is based on the real cover of VOGUE August 2004 issue, featuring Priscilla Presley, Lisa Marie Presley and Riley Keough.
Gisele Bündchen agreed to be in the movie only if she didn't play a model. Stanley Tucci was one of the last actors cast. Daniel Sunjata had originally read for Tucci's part, rather unenthusiastically since he had just finished playing a similar character, but then read the Holt part and asked if he could audition for it. Simon Baker auditioned by sending a video of himself, wearing the same self-designed green jacket he has on when he and Andrea meet for the first time.
In the last scene between Miranda and Andy, Andy asks Miranda if the lifestyle that Miranda led wasn't what she wanted. Miranda responds, "Everyone wants this. Everyone wants to be us." The original line was "Everyone wants to be me." However, Meryl Streep did not like this line, finding it too self involved and dramatic. At the table reading of the script, Meryl organically changed the line to "Everyone wants to be us." The line change stuck and was used in the film.
The idea of having Miranda appear without any make-up in the scene where she opens up to Andrea and worries about the effect of her divorce's public disclosure on her daughters was Meryl Streep's idea.
In one of the original drafts, Miranda explains how she started out as an assistant and worked her way up. It is also revealed where she grew up: Pearl River, New York. The scene then continues on to the scene of Miranda confessing her divorce to Andy. This however isn't true to the book as Miranda was born Miriam Princhek, to orthodox Jews, in the East End of London and started off as an assistant to an English designer. She became well known in London fashion and started learning French at night to soon become junior editor of Chic magazine in Paris. At 24 she changed her name to Miranda Priestly, replaced her rough, London accent with a sophisticated one before spending 10 years at French Runway before she was transferred to New York.
Author of the original novel, Lauren Weisberger, reportedly based the the character Emily upon Plum Sykes, writer and former assistant to Vogue editor-in-chief Anna Wintour. Sykes worked at Vogue at the same time as Weisberger.
The novel sold over a million copies, spent ten weeks at No 1 and spent a year on the New York Times bestseller list; the film was also a box-office smash hit. The novel has since been published in 40 languages.