SQL 2008 R2 Service Pack 1 (SP1) available for download.

Maybe you have read it already but since 11 july 2011 Microsoft SQL Server 2008 R2 Service Pack 1 is available for download. See: http://www.microsoft.com/download/en/details.aspx?id=26727

Beside a lot of bugfixes which are listed in this Master KB article , some existing functionality is improved: .

1. Dynamic Management Views for increased supportability: sys.dm_exec_query_stats DMV is extended with additional columns to improve supportabilities over troubleshooting long-running queries. New DMVs and XEvents on select performance counters are introduced to monitor OS configurations and resource conditions related to the SQL Server instance.
2. ForceSeek for improved querying performance :Syntax for FORCESEEK index hint has been modified to take optional parameters allowing it to control the access method on the index even further. Using old style syntax for FORCESEEK remains unmodified and works as before. In addition to that, a new query hint, FORCESCAN has been added. It complements the FORCESEEK hint allowing specifying ‘scan’ as the access method to the index. No changes to applications are necessary if you do not plan to use this new functionality.
3. Data-tier Application Component Framework (DAC Fx) for improved database upgrades:The new Data-tier Application (DAC) Framework v1.1 and DAC upgrade wizard enable the new in-place upgrade service for database schema management. The new in-place upgrade service will upgrade the schema for an existing database in SQL Azure and the versions of SQL Server supported by DAC. A DAC 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. For more information, see Designing and Implementing Data-tier Applications.
4. Disk space control for PowerPivot:
   This update introduces two new configuration settings that let you determine how long cached data stays in the system. In the new Disk Cache section on the PowerPivot configuration page, you can specify how long an inactive database remains in memory before it is unloaded. You can also limit how long a cached file is kept on disk before it is deleted.