Microsoft has released second service pack for SQL Server 2008 R2 (10.50.4000.0). It contains generally all hotfixes provided in SQL Server 2008 R2 SP1 CU 1 to 5. Some of the hotfixes are highlighted at Technet’s blog:
Reporting Services Charts Maybe Zoomed & Cropped
Customers using Reporting Services on Windows 7 may sometime find charts are zoomed in and cropped. To work around the issue some customers set ImageConsolidation to false.
Batch Containing Alter Table not Cached
In certain situations with batch files containing the alter table command, the entire batch file is not cached.
Collapsing Cells or Rows, If Hidden Render Incorrectly
Some customers who have hidden rows in their Reporting Services reports may have noticed rendering issues when cells or rows are collapsed. When writing a hidden row, the Style attribute is opened to write a height attribute. If the attribute is empty and the width should not be zero.
For more information see KB article #2630458
Yet there is no KB available for Service Pack 2 although it is referenced in download details:
There are three Service Pack ‘mutations':