Talented indie princess Olivia Thirlby (“Juno,” “The Wackness”) has signed on for a mainstream role, playing an American trust funder whose Moscow vacation is interrupted by an alien invasion, according to The Hollywood Reporter. Summit and New Regency are bankrolling the promising-sounding “The Darkest Hour,” which is being produced by Russian director Timur Bekmambetov (“Wanted”) this summer in Russia. It’s the directing debut of art director Chris Gorak (“Fight Club”), who wrote the script with Josh Zetumer. THR is also reporting “exclusively” that the long-in-limbo “Love Ranch” has found a distributor, something I could swear I had last Friday.