(Via Greg Blood and Chris Gould, NSIC, Canberra)
The Joint Steering Committee (JSC) for the Development of Resource Description and Access (RDA) states that RDA is the working title of the new standard that will be the successor to AACR2. (Background information is here.)
RDA will provide:

• A flexible framework for describing all resources – analog and digital
• Data that are adaptable to new and emerging database structures
• Data that are compatible with existing records in online library catalogues

Information about the RDA full draft can be found here.
This is an information page about RDA on the National Library of Australia website. This is a link to presentations about RDA made at a seminar in Sydney in October 2008.