I was quite disappointed when I saw this trailer to be honest.
I adore Keira and I have a huge thing for Ralph Fiennes and I was really excited about them being in a film together. It would be nice to see Ralph with someone half his age instead of twice his age for a change. My disappointment could have a lot to do with their lack of chemistry, at least in the trailer, but then again they're not supposed to have chemistry because they're unhappily married.
I thought it looked rather like your average period piece and I wasn't very intrigued by the characters, storyline or anything else. Let's hope it gets better the more footage we get to see.