Media mogul Jason Binn is staffing up his latest startup, Du Jour. The print magazine and Web site are launching in September, in partnership with Gilt Groupe and Hudson News Media’s James Cohen. We’re told Elle.com editorial director Keith Pollock is leaving his post to join as Du Jour co-editor. Known as a fashion industry fave, Pollock’s appeared on Elle creative director Joe Zee’s Sundance Channel series “All on the Line,” and worked at Interview magazine’s Web site as well as Style.com’s men’s site.