The DataSet Designer has been enhanced to allow data sources to be switched from connected to disconnected with zero code changes. This allows tables coming from a server data store and tables coming from a client data store to be represented within one model.
Sync Services for ADO.NET is a part of Microsoft Sync Framework, "a synchronization platform enabling collaboration and offline access for applications, services, and devices."
SQL Server 2008 Change Data Capture is designed to capture insert, update, and delete activity applied to SQL Server tables, and to make the details of the changes available in consumable relational format. "The change tables used by change data capture contain columns that mirror the column structure of a tracked source table, along with the metadata needed to understand the changes that have occurred."