I’ve updated the Ruby on Rails Tutorial book to use the recently released Rails 4.0 final. I’ll give people a chance to look at it for a week or two and then switch it over to the default at railstutorial.org. I also plan to produce a supplementary screencast on Rails 4.0, updating the book’s sample app and covering some of the relevant diffs with Rails 3.2.
Within a few weeks, I expect to release the supplementary screencast and ebook of the 4.0 version as a standalone product, available at a large discount to current customers. Once I feel the changes in Rails justify the effort (probably later this year), I plan to produce a full new 3rd edition and a new screencast series. These will also be available at a discount to current customers.
The full 3rd edition will include everything in the current version, as well as some optional updates to the RSpec syntax for integration tests and probably some coverage of Turbolinks and Russian-doll caching. I also anticipate there being a new Rails release or two before then, presumably bringing some additional changes.
It’s worth bearing in mind that the purpose of the Rails Tutorial is to teach web development with Rails, not principally to keep people up-to-date on the latest Rails techniques. In the context of an introductory tutorial, the differences between Rails 3.2 and Rails 4.0 are minor. If you are already an experienced Rails developer and want to keep up with latest techniques in Rails, I recommend Ryan Bates’s RailsCasts.