When Devil Wears Prada comes out, there were some interviews where Meryl Streep made very positive comments about Emily Blunt but not about Anne Hathaway, and some suggestion was made that she was not impressed by Anne Hathaway, although for career reasons Anne Hathaway wanted to keep on the right side of Meryl Streep.
But still, I love both Anne Hathaway and Meryl Streep!