Sandra Bullock Gravity (A.Cuaron)
Annette Bening The Great (G.Armstrong)
Cate Blanchett Carol (J.Crowley)
Cate Blanchett Untitled Woody Allen Project (W.Allen)
Marion Cotillard Low Life/Untitled James Gray Project (J.Gray)
Kate Hudson The Reluctant Fundamentalist (M.Nair)
Helen Hunt Decoding Annie Parker (S.Bernstein)
Helen Hunt Relative Insinity (L.Moss)
Nicole Kidman The Railway Man (J.Teplitzky)
Jennifer Lawrence Serena (S.Bier)
Samantha Morton Decoding Annie Parker (S.Bernstein)
Elisabeth Olsen Therese Raquin (C.Stratton)
Gwyneth Paltrow 33 Dias (C.Saura)
Julia Roberts August : Osage County (J.Wells)
Meryl Streep : August : Osage County (J.Wells)
Hilary Swank The Dallas Buyer’s Club (J.-M. Vallée)
Emma Thompson Saving Mr. Banks (J.-L. Hancock)
Mia Wasikowska Carol (J.Crowley)
Emily Watson The Poisoners (J.Amiel)
K.Winslet Labor Day (J.Reitman)
Reese Witherspoon Big Eyes (S.Alexander/L.Karaszewski)
Naomi Watts Caught in Flight (O. Hirschbiegel)
Naomi Watts Two Mothers (A.Fontaine)
Robin Wright Two Mothers (A.Fontaine)
Others
Kidman
Bullock
Streep
then hopefully Emma Thompson...
then a newbie
In terms of potential first-time nominees, I think Julie Delpy is towards the top of that list, atm