According to TV Guide, Farmiga will play Norman Bates's mother:
A&E's upcoming series Bates Motel has found a mother for young Norman Bates — and this time it's not a skeleton in a wig. Vera Farmiga, who carried on a salacious affair with George Clooney in 2009's Up in the Air, will play Norma Louise Bates.
"We are delighted to welcome Vera Farmiga to Bates Motel," says executive producer Carlton Cuse (of Lost fame). "She is a phenomenal talent who has demonstrated incredible range and intelligence in a number of landmark film roles, and we couldn't be more excited to have her join our project."