One of the major reasons for using a framework like rails is to take advantage of open source code that frees you to spend time focusing on your company's core

One of the major reasons for using a framework like rails is to take advantage of open source code that frees you to spend time focusing on your company's core competencies. Some of the most useful gems in the rails ecosystem no longer (or never did) support rails 2. This is the biggest reason in my mind, but release notes on rails 3 itself are here http://edgeguides.rubyonrails.org/3_0_release_notes.html http://edgeguides.rubyonrails.org/3_0_release_notes.html