Pretty simple Webapp that you could have done 7 years ago. That not necessarily a bad thing but I wouldn't develop a webapp with those tools.
Specifically the 'Component' library. I really didn't enjoy working with it and it one of the most complex to understand parts of our web application.
So while this seems like a fun set of slides (I have not watched the presentation yet), it's not what I would call a great introduction to Web development in Clojure overall.