I see that there are a lot of success stories using CloudFormation, we're planning to use it to make sure our Prod/Dev environments are identical. I heard that its a a great place to have a single file, in version control, for deploying multiple similar environments. 
I've a doubt, lets say if I use CloudFormer and create a template of say my DB instance and save it GIT, and say in next 10-15 days I make couple of changes like add new volumes in instance to store DataFiles, or delete some volumes etc, Now, when I use that Template in say our Dev Environment will it reflect the volumes which I added/deleted. I mean how does it work behind the scene.