You are contrasting the versions incorrectly. Rails 3.0 may have been released then but the latest version of it is Rails 3.0.9, which was released < 1 month ago.

I was just interested in these books about the "latest" version of rails. Are they about Rails 3.0.9?

The Rails 3 Way - Published December 20, 2010, I doubt it includes the 3.0.9 release. Ruby on Rails 3 Tutorial - Published on December 26, 2010, also doubt this book covers 3.0.9 Agile Web Development with Rails - March 31, 2011 - don't know about this one.