Installing Visual Studio 2010 SP1 will cause the Intellisense feature of SQL Server 2008 stop working.
So Visual Studio 2010 SP1 breaks SSMS 2008 R2's IntelliSense. There is a connect about that, and fortunately there is also a fix for that.
(In short, you will need to install Cumulative Update package 7 for SQL Server 2008 R2 by requesting
SQLServer2008R2_RTM_CU7_2507770_10_50_1777_x86or
SQLServer2008R2_RTM_CU7_2507770_10_50_1777_x64
from this hotfix request page.)

