It was done as part of some changes to add back support for custom new actions e.g. /posts/new/preview. To support this we added new scope to resources to match member and collection scopes. So whereas before 'new' would be added to the path scope, in RC it doesn't because new_scope has already added new to the path.
You can specify your routes as follows to get the effect you need:
resources :sections, :id => /.+/ do
get :new, :path => 'new', :on => :member
However you'll still need to address the create, edit and update actions plus you'll need to override the :id constraint which doesn't allow slashes. Also the show action comes before the edit action so the greedy regexp needed for :id will match the edit url. You would be better off manually specifying each of the routes individually - it'll be easier than trying to bend resources to what you want:
scope('sections', :controller => 'sections', :id => /.+/) do
get '/(:id)/new' => :new, :as => :new_section
get '/:id/edit' => :edit, :as => :edit_section
get '/:id' => :show, :as => :section
put '/:id' => :update, :as => :section
delete '/:id' => :destroy, :as => :section
get '/' => :index, :as => :sections
post '/(:id)' => :create, :as => :sections
This set of routes should do what you need.