Seems like a lot of people are getting excited about Trails, and rightly so. I can see a large number of projects getting built this way. It's a great idea, it's developer-focused, it gets you great results fast. I've also seen Chris mention integrating Ajax components from Tacos. What's easier than using Tacos components for Ajax behavior ... using Trails and getting the Ajax stuff for free!
By the way, one of the most remarkable aspects of Trails is that Chris has been building Trails as a way to learn Tapestry. Either Chris is really some kind of comic-book alien machine super-intelligence (unlikely, I've met him in person), or Tapestry isn't quite as hard to learn as some people seem to think. Perhaps Chris had less Struts and JSP clutter to unlearn.