Chuck just did this video which provides the basics for how to add our new Order Status and Order History functionality into an existing store. Since we no longer make any template code changes you'll have to do these manually as we can't possibly predict how you'll want it in your customized store.
http://www.merchanttutorials.com/Pub...adedStore.html
http://www.merchanttutorials.com/Pub...adedStore.html