'Downton Abbey': Who's in and who's out for Season 4

Season 3 of “Downton Abbey” just ended a few weeks ago (and we’re still in mourning, by the way; RIP, Matthew), but lots of casting changes are already underway for the hit British drama’s much-anticipated fourth season. In fact, the front door of Lord Grantham’s estate might as well be revolving, with all the “Downton” cast members coming and going these days.

With no new episodes arriving here for another year or so (filming on Season 4 just began in the U.K.), we have plenty of time to speculate wildly about what all of these changes mean. So here’s a quick rundown of which “Downton” stars won’t be back next season… and which fresh faces will take their place.

Who’s Out

Dan Stevens (Matthew)

Millions of viewers let out a collective gasp when Mary’s loving husband Matthew Crawley was killed at the very end of last month’s Season 3 finale. (The ones who didn’t read online spoilers, anyway.) Stevens has swiftly moved on, though, making his Broadway debut opposite Jessica Chastain in “The Heiress” and co-starring with “Sherlock’s” Benedict Cumberbatch in the upcoming WikiLeaks film, “The Fifth Estate.”

Jessica Brown Findlay (Sybil)

Matthew wasn’t the only Crawley to head up to that big hunting lodge in the sky: Youngest daughter Sybil tragically died during childbirth in a wrenching episode. Like Stevens, Brown Findlay opted not to renew her three-season “Downton” contract, and she’s striking while the iron’s hot with a pair of big film roles. She’ll co-star with Amy Adams and Jennifer Hudson in the family drama “Lullaby” and play Colin Farrell’s love interest in the romantic fantasy “Winter’s Tale.”

Siobhan Finneran (Miss O’Brien)

We can’t exactly say we’ll miss spending time with Miss O’Brien, the perpetually scowling maid played by Finneran. But it’s still sad to see another key cast member exit the show, no matter how evil they are. “Downton” producers say it was Finneran’s choice to leave, and though O’Brien wasn’t killed off, the series did pave the way for her exit, with her cozying up to Rose’s awful mother and Mr. Bates holding “her ladyship’s soap” over her head.

[Related: When Did 'Downton Abbey' Become Such a Downer? A Season 3 Post-Mortem]

Who’s In

Tom Cullen

Mary will be a widow when Season 4 begins, but life does go on. The smoldering Cullen, who starred in the acclaimed indie film “Weekend,” will play Lord Gillingham, an old family friend of the Crawleys who is a possible love interest for Lady Mary. But can viewers warm to a new man in Mary’s life so soon after Matthew’s death? (At least we have a year to get used to the idea.)

Dame Kiri Te Kanawa

Cora’s mom Martha won’t be the only singer in Downton next season. A world-renowned opera soprano from New Zealand, Te Kanawa brings her golden pipes to “Downton,” playing a guest of the Crawleys. And yes, we can expect her to belt out a tune or two.

Nigel Harman

The downstairs crew gets reinforcements with the addition of Harman, a veteran of the long-running U.K. soap “EastEnders.” (So he has some experience with outrageous plot twists.) Harman will play a visiting valet who works his charms on some of the female staff. Jimmy, you have some competition.

[Photos: See What the 'Downton Abbey' Cast Looks Like Out of Costume]

Dame Harriet Walter

The Dowager Countess will have a peer to exchange biting quips with: Walter joins the cast as Lady Shackelton, an old pal of Violet’s. Walter is no stranger to playing posh types, having co-starred in “Sense and Sensibility” and “Atonement.” (And like Maggie Smith, Walter is a dame… so they’ll have plenty to chat about.)

Julian Ovenden

Lord Gillingham’s not the only one vying for the attentions of the widowed Lady Mary: London stage star Ovenden (“Finding Neverland”) will play aristocrat Charles Blake, who also makes a play for Mary’s wounded heart. Is it too much to hope that one of these handsome fellas might take an interest in poor Edith? It is, isn’t it?

Joanna David

A veteran of British period dramas (“Bleak House,” “Pride & Prejudice”), David will add even more class to Downton when she guest stars next season as the Duchess of Yeovil. Our knowledge of British titles is a little rusty, but that sounds pretty fancy to us.