thats astonishing!!!!
Merb, the ruby framework famous for modularity and performance, is joining hands with Rails, the more popular one. In short, the Rails 3.0 will -
1. see improvement in performance
2. be modular: User can add/edit/remove functionality modules as needed. say user can replace ActiveRecord with DataMapper, or Scriptaculous with jQuery easily.
3. have public API for plugin developers. So, less chance of code break in framework upgrade
See here -
http://weblog.rubyonrails.org/2008/12/23/merb-gets-merged-into-rails-3
http://yehudakatz.com/2008/12/23/rails-and-merb-merge/Its indeed a good for the whole ruby community :)
thanks,
-Yeameen