I haven't actually heard of this directly but by other blogs like Enchanted Serenity Of Period Films and Jane Austen Today, both very cool places to learn neat stuff. I like this rumor because i love Jane Austen movies, so i think people will be very excited, i know i am.
The very well known actress Romola Garai (Atonement, Vanity Fair, Nicholas Nickleby, and As you like it) will play (by rumor) the beloved Emma Woodhouse. And Jane Austen Today says that Jonny Lee Miller (1999 version of Mansfield Park, and series Eli Stone) will play Mr. Knightly, their are some other characters that have been cast also. It will be the production of BBC One and four hours are said to the the time of it.
I can't wait to enjoy the movie.