Jennifer Lawrence is playing a person with a manic-depressive (bipolar) disorder, the movie is getting great reviews, so I see why she's getting the press. And I would be very happy if she wins, I love her. However, I do understand what you guys are saying, it's weird because it's a romantic comedy, and those usually don't do well at the awards. At least not in a long time, The last actress to win for a romantic comedy was Helen Hunt in As Good as It Gets in 1997.
Marion Cotillard also seems like a great choice to me. Jessica Chastain, I love her, but she can wait a few more years.