I've just put together a 6 minute screencast about Tapestry 5. It covers creating a new project (using Maven), setting up dependencies and structure, and creating a page template and seeing changes to the live application when you change a Java class.
Class reloading is a key feature of Tapestry 5 and is exceptionally important to the stellar productivity Tapestry 5 will enable. Just as people fastened on to the Tapestry 3/4 templating system, I think many people will fasten on to class reloading. Don't be mistaken; there's a lot more to this enchilada than that one feature. But it's a great feature to hook people early on!