Here's where it's useful. If you want an alternative to the DROP and CREATE method of maintaining stored procedure scripts - which would overwrite metadata about when a procedure was first created - you can use this:
IF OBJECT_ID ( '[dbo].[NewProcedure]', 'P' ) IS NULL
EXEC ('CREATE PROCEDURE [dbo].[NewProcedure] AS')
ALTER PROCEDURE [dbo].[NewProcedure]
-- Procedure code goes here
Just an idea.