One of the best things about Rails is that it's under constant development. New features appear constantly, and the upcoming 3.0 release even streamlines the architecture substantially. This wonderful track record of incremental development gives developers an ever-better set of tools to work with, but is really difficult for those of us documenting those tools in old-fashioned ink and paper.
I'm very happy to announce that O'Reilly has released the Live Edition of Learning Rails, which brings the book up to date from its original November 2008 release (covering Rails 2.1.0) to last month (covering Rails 2.3.5), as well as incorporating errata. Right now, the Live Edition is available only electronically, but we hope to have print on demand as well sometime in the not too distant future. Readers using Safari Books Online will also have access to the Live Edition soon.
If you buy the Live Edition, you'll get electronic updates through the next full edition of the book. In this case, the Live Edition will include the Rails 3.x versions, as they're coming up very quickly. We've already started work with the Rails 3.0 beta, most of which isn't that drastic a shift, but which has some basic changes that will definitely make it difficult for beginners to use the older books.
This is a pilot project, and we still have a lot to figure out. Because it's on a continual update cycle, there won't be a copyedit until the next full edition. Hopefully readers will tolerate that in favor of updated coverage. (It is, at least, much easier to fix typos, and there's less need to check the errata page!)
We have a lot of other questions, though. Do we keep versions covering Rails 2.x available when 3.x comes out? Are Learning customers interested in a version that covers the Rails 3.0 beta? How far should we go in making other changes to the book?
Let us know what you think, and that input will help guide us. We're also getting ready for more Live Edition projects, so there will be more news soon!