Maggie Smith as the Dowager Countess, left, and Hugh Boneville as Lord Grantham. (Nick Briggs/PBS/AP)

Michael Ausiello at TV Line reports that Michelle Dockery (Lady Mary), Elizabeth McGovern (Cora), Hugh Bonneville (Robert), Joanne Froggatt (Anna) and Brendan Coyle (Bates) have signed on for seasons four and five.

Season two of the soapy British drama recently ended in the U.S. and season three, which will feature Shirley MacLaine as Lady Grantham’s mother, just started production. New episodes are set to air in the U.K. in September and stateside in 2013.

Now for the bad: Dan Stevens (Matthew), Siobhan Finneran (O’Brien) and Jessica Brown Findlay (Lady Sybil) have not signed contracts at this point, according to TV Line. (Stevens has a Twitter account, if anyone wants to send him pleading tweets) Neither has Maggie Smith, who plays the Dowager Countess, according to the Telegraph U.K. The last piece of news has proved rather upsetting to some.

Smith’s Dowager Countess is undoubtedly one of the jewels in the “Downton” crown. One only needs to hear her one-liners (compiled in a “[Stuff] the Dowager Countess Says” video perfectly) to understand what makes the character great.

It’s easy to see why Smith’s departure would be a loss to the show and to its viewers. But is it really that hard to imagine the 77-year-old Smith leaving “Downton”? Shouldn’t we instead wonder if the show will go on past season three?

Last October, show creator Julian Fellowes told the Radio Times that he planned for “Downton” to unfold in three parts: “The original concept in my optimistic head was for the first series to start towards the end of the Edwardian era, the second to be set during World War One and the third in the 1920s. In the 20s there are big changes, new inventions, different expectations I can't wait to explore.”

He recently told the BBC that he hasn’t even finished the script for season three. Of a fourth season, Fellowes said, “I think I'd be disappointed if there wasn't a series four, but I wouldn't say more than that.”

It’s fair to say that there are a lot of variables at the moment and we shouldn’t panic about a Smith-less “Downton” just yet. As they Dowager Countess would tell us, “Don’t be defeatist, dear, it’s very middle class.”

View Photo Gallery: The popular period drama has reintroduced WWI-era style to international audiences and has fueled several fashion trends seen on runways and celebrities this year.