The railsmachine gem has been updated for Capistrano 2 compatibility. Better late than never, right?

Not much has changed but the use of namespaces. The typical deployment will look like this: 
capify .
railsmachine -A . -n yourapp -d yourdomain.com
cap repos:setup
cd ..\yourapp_machine
cap servers:setup deploy:cold
 You can find more details on our support page. Upgrading? Run the first two commands above, and commit your changes. If you have hooked tasks, you’ll also need to update those. A task like this: 
task :after_deploy, :roles => :app do
  # ...
end
 might become this: 
namespace :custom do
  task :update, :roles => :app do
    # ...
  end
end
after :deploy, 'custom:update'