The article was in no way meant to be a definitive resource, just an attempt to continue helping new Rails developers learn how to work with the framework. The many useful comments I've received will help improve the article a lot.
On the other hand, if you want to follow the tutorial and make a definitive version of the code yourself (preferably with tags for each chapter end), I'd be happy to throw it up on GitHub. And you might just get a nod in the acknowledgments. ;-)
I'll reiterate that I recommend highlighting gemcutter. qrush and the contributors have done an excellent job with it, it contains examples of how to approach a variety of tasks (even has examples of using metal, middleware and embeddable sinatra), the code is clear and adheres to conventions and it's used in a real production app that every Ruby developers has contact with.