Problem executing simple model#to_json

I was unable to duplicate this issue on master:

➜  ticket_4015 script/rails g model user name:string
➜  ticket_4015 rake db:migrate
(in /Users/dtrasbo/code/rails/railties/tmp/ticket_4015)
➜  ticket_4015 script/rails g controller users index
➜  ticket_4015 script/rails c
Loading development environment (Rails 3.0.0.beta4)
ruby-1.9.2-preview3 > User.create(:name => 'David Trasbo')
 => #<User id: 1, name: "John Smith", ...> 
ruby-1.9.2-preview3 > User.create(:name => 'Marc Hejner')
 => #<User id: 2, name: "David Trasbo", ...>

class UsersController < ApplicationController
  def index
    @users = User.all
    respond_to do |format|
      format.json { render :json => @users.to_json(:only => :name) }
    end
  end
end

Response body for http://localhost:3000/users.json:

[{"user":{"name":"John Smith"}},{"user":{"name":"David Trasbo"}}]

This ticket can be closed.

Closable, see above.