是因为sql server team修改了t-sql error的生成方式导致了这个bug.这个错误会在4月中旬出修正补丁。CU7里面会修正The SQL team made a change to the way an error message is constructed in the TSQL Language Service in Dev10 SP1. This change caused a loss of Intellisense when SSMS SQL Server 2008 R2 and Dev10 SP1 are installed. The team is issuing a fix that will be available in an upcoming SQL Server 2008 R2 CU (CU#7 scheduled for mid-April) and in SQL Server 2008 R2 SP1.
http://blog.sqlauthority.com/2009/03/31/sql-server-2008-intellisense-does-not-work-enable-intellisense/
http://blog.csdn.net/downmoon/archive/2011/04/15/6325150.aspx