Who's Holding Out on Downton Abbey?

Now that Downton Abbey has taken both sides of the pond by storm, it's time to re-up for the residents of our favorite English manor.

But which cast members have yet to sign on for seasons four and five?

TV Line is reporting that Dan Stevens (Matthew), Siobhan Finneran (O’Brien) and Jessica Brown Findlay (Lady Sybil) are among the holdouts for now. What would Downton Abbey be without its (maybe) heir, Matthew?

Cast members who are on board for future seasons include Michelle Dockery (Lady Mary), Elizabeth McGovern (Cora), Hugh Bonneville (Robert), Joanne Froggatt (Anna) and Brendan Coyle (Bates). So I guess that means Bates won't waste away in prison after all? (Was there ever any doubt?)

No word yet on Maggie Smith, who is arguably the most valuable member of the cast as the very quotable Dowager Countess.