I just upgraded an app from 3.0.7 to 3.1.0 rc1

I use Devise and Mongo Mapper. The Mongo Mapper for Devise gem depends on Devise 1.1.x, and this causes a bunch of deprecation warnings, but it works. I don't know if the latest Devise has this fixed, as I can't run it due to the Mongo Mapper for Devise dependency.

Some hand editing of development.rb to remove the debug_rjs setting and some editing to change my use of stylesheet_tag and my app ran ok

I'm not using the cool new asset pipeline yet, but my app runs with 1 hour of work.