Rails 3 is going to be release.The new version of Rails will incorporate Merb features such as improved performance, support for jQuery and a simpler routing API for better REST support. Inspired by Merb, Rails 3 will also incorporate an API to make plug-ins easier to add and manage and become "test framework agnostic" to support rSpec as well as traditional unit tests.
Rails 3 is not just about Merb features; a mechanism to protect against cross site scripting attacks, easier complex queries in ActiveRecord, ActiveModels to abstract functionality from ActiveRecord to help support non-SQL back ends and a new way of packaging Rails applications, will all feature in Rails 3.