Cannot assign a default value to a local variable

Msg 139, Level 15, State 1, Line 1
Cannot assign a default value to a local variable. 

Prior to SQL Server 2008, assigning a default value (or initial value) to a local variable is not allowed; otherwise this error message will be encountered.

This error message can easily be generated using the following DECLARE statement entered in either SQL Server 2000 or SQL Server 2005.

DECLARE @CurrentDate DATETIME = GETDATE()

Msg 139, Level 15, State 1, Line 0
Cannot assign a default value to a local variable.

SQL Server now allows the assigning of a value to a variable in the DECLARE statement.