I've not seen the film, so I'm not going to judge her performance in it via the box office takings. However, she does have a good chance this year as there is a complete dearth of competition in the field.
I think the nomiations will be Merly Streep (Julie & Julia), Carey Mulligan (An Education), Gabourey Sidibe (Precious) and Saoirse Ronan (The Lovely Bones), with the last place a toss up between Penelope Cruz (Broken Embraces) and Sandra.
There isn't really any front-runner, so if she was ever going to win an Oscar, this is probably her best chance.