A morning mix of entertainment headlines...

Sean Penn, at the Guys Choice Awards in June, has apparently chosen a new girlfriend. (Kevin Winter/GETTY IMAGES)

Melissa Gilbert has filed for divorce from actor-husband Bruce Boxleitner. The two separated earlier this year after 16 years of marriage. Gilbert is seeking joint custody of their 15-year-old son, Michael. (Associated Press)

David Arquette is rumored to be one of the contestants on this season’s “Dancing With the Stars” after he was spotted heading into the show’s rehearsal studio. ABC will announce this year’s line-up during Monday’s episode of “Bachelor Pad.” (The Wrap)

Justin Bieber will make the holidays bright this year; he’s releasing a holiday album, which will mark his second studio release. Let’s hope he does a cover of “Grandma Got Run Over by a Reindeer.” (MTV)

Kris Jenner will be a guest host on the “Today” show in October. This news follows the announcement that the mother of Kim Kardashian also will be a temporary replacement for Sharon Osbourne on “The Talk.” That gig will only last two weeks, while Osbourne is on a leave of absence. (Hollywood Reporter)

Dan Aykroyd says “Ghostbusters 3” will be made with or without Bill Murray. Fine. But will Rick Moranis be involved? (Digital Spy)

Britney Spears discusses her back-up career plans, after the jump.

Britney Spears says if she wasn’t a pop star, she probably would be a teacher. Please join me in encouraging Spears to continue her thriving music career. (Us)

Natalie Portman turned down the lead in the movie “Adaline,” a film about a woman who stops aging after an accident. (Entertainment Weekly)

Chord Overstreet opted not to return to “Glee” as a recurring character because he wants to focus on his music career. (Vulture)