Yes, we absolutely will be. We were running 1.9.1 (can't remember which patch level off hand) in a stable config with Rails beta 1, but as the Rails beta progressed, we were unable to move forward with ruby 1.9.1 underneath. This morning, we moved our staging environment to ruby-1.9.1-rc2 and rails-3.0.0.beta4. All our testing since this morning has gone 100% smoothly (thank god!). Every increment in beta before this point has been a nightmare.