The official cast list for the 2011 Downton Abbey Christmas special does not list Jessica Brown Findlay among the cast. I wonder if Jessica, who plays Lady Sybil Crawley, will be back for the new season next year? Obviously she goes off and marries Branson but does that mean that Lady Sybil has disappeared for good? I hope not. Also, Julian Fellowes is known for deliberately pulling rabbits out of hats, so he's probably left her off the cast list deliberately to make us all think. She isn't in any of the official photos, though, and that could have more meaning.
Guess we'll have to wait and see.