From the press release:
The Board of Governors of the Academy of Motion Picture Arts and Sciences has approved additional rules for the 85th Academy Awards. The most significant changes affect the Original Song category, in which there will now be five nominees.
During the nominations process, all voting members of the Music Branch will receive a Reminder List of works submitted in the category and a DVD copy of the song clips. Members will be asked to watch the clips and then vote in the order of their preference for not more than five achievements in the category. The five achievements receiving the highest number of votes will become the nominations for final voting for the award.
Additionally, upon the recommendation from the Designers Branch (formerly the Art Directors Branch), the Art Direction award will be known as the Production Design award.