Possibilities

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Sandra Bullock - "Gravity"
No actress in 2012 has to face a tougher physical challenge than Sandra Bullock in Alfonso Cuaron's "Gravity" -- the 2010 Oscar-winner has to carry the vast majority of the film on her own, acting mostly against CGI, while being suspended in an approximation of zero-gravity, in a spacesuit. There's no reason to think she won't be able to pull the part off: the big question is, will Academy members be able to get past the genre nature of the film?

Carey Mulligan - "The Great Gatsby"
Since breaking out in "An Education" (for which she was nominated for Best Actress), Carey Mulligan has turned in excellent performances in everything from "Never Let Me Go" to "Shame," but further Oscar gold hasn't followed. But if ever a part could give her another chance, it's Daisy, the love of Jay Gatsby's life, in "The Great Gatsby." If she wasn't already the most sought-after actress in Hollywood, it's the kind of part that would make her so, and no one's doubting her skills at this point. It's possible that she might campaign in Supporting Actress, but given that she has a good chance there too, for The Coen Brothers' "Inside Llewyn Davis," we imagine she'll want to spread the love.  

Smashed
Mary Elizabeth Winstead - "Smashed"
While alcoholism drama "Smashed" didn't quite get the same buzz as fellow Sundance hit "The Surrogate," it got very enthusiastic reviews, most notably for lead, "Scott Pilgrim Vs. The World" star Mary Elizabeth Winstead, who carries the picture as a schoolteacher trying to kick the bottle. With Sony Pictures Classics, who took Carey Mulligan and Anne Hathaway to nominations in the last few years, picking the movie up, this could gain momentum as the year goes on, if the critics in general match the Park City enthusiasm. All that being said, she's a brand-new name in Academy circles, which may not help against familiar faces like Knightley and Linney.

Rachel McAdams - "Untitled Terrence Malick Project"
As we said above, Terrence Malick has not, as yet, led to any actors getting an Oscar nomination. But from what little we know about his next, which seemingly focuses on good old-fashioned affairs of the heart, it might be more relatable to Oscar voters. And Rachel McAdams might be the biggest beneficiary of that. That is if she's given more to do than Jessica Chastain in "The Tree of Life," and if the film actually comes out in 2012.