Wel I've almost completely read the book while I was away on a summer holiday. I still like the book. Specially the Web 2.0 part has been improved very much. Also the RESTful routes part is interesting, but I don't see the direct need for it.
I still need to read the part about deployment, but after a quick peek, I think it's much completer and more mature then the description in the first book. Also it shifted the usage advice from fastcgi to Capistrano. Well an interesting chapter.
The Ajax part also hinted me about the "readystate 3" problem, which simply means that the web server should not use keep-alive with ajax. It looks like this is the problem I've encountered with a project of mine... Need to figure this out!