Great set of slides - I wish I could have heard the talk live. I did add his company's blog to my RSS/Atom feed.
I would like to spend more time with both Clojure and AppEngine and the slides were some motivation. I am still a little skeptical however that Clojure base web apps will ever have the traction of Rails (I had a 5 hour sprint today to add two major features to a customer's rails web app: would have taken a long time to do with server side Java; I would guess that Clojure would split the difference).
I've bought 3 Clojure books, and I would by a 4th if the author of these slides would write a web app specific Clojure book.