"You can deploy, upgrade, register, extract and delete DACs," Microsoft said. "SP2 does not upgrade the SQL Server 2008 client tools to support DACs. You must use the SQL Server 2008 R2 client tools, such as SQL Server Management Studio, to perform DAC operations. A data-tier application is an entity that contains all of the database objects and instance objects used by an application. A DAC provides a single unit for authoring, deploying and managing the data-tier objects. "
Microsoft has release an update for SQL Server 2008 that provides enhancements for reporting and management.