I realise this is a very similar question to Stop SSMS from scripting SPs using sp_executesql?
However, they seem to have changed the behaviour with SSMS 2012.
I
The closest you can get to this functionality is to go under tools, options, SQL Server Object Explorer, Scripting, then set the Check for Object Existing to false.
The drawback is that if you do this then drops and creates will always try to drop even if the object does not exist. The ideal solution would be a setting that allowed your script to look like the example below for creating Views, Procedures, and User-Defined Functions.
/****** Object: View [dbo].[vEmployees] Script Date: 9/14/2012 9:18:57 AM ******/
IF EXISTS (SELECT * FROM sys.views WHERE object_id = OBJECT_ID(N'[dbo].[vEmployees]'))
DROP VIEW [dbo].[vEmployees]
GO
CREATE VIEW [dbo].[vEmployees]
AS
SELECT DISTINCT
Employees.EmployeeID,
FirstName,
LastName
from
Employees
JOIN Sales on Employees.EmployeeID=Sales.EmployeeID
GO
In short if the scripting engine thinks of the drop and create together in checking for object existance it does not need to put the condition on the create.