[Rails] Changes with mountable engines in 3.2?

So, let's say I create a mountable engine using Rails 3.1.3 and do the
following:

rails plugin new blank_engine_test --mountable
cd blank_engine_test/
rails s

I get this:

=> Booting WEBrick
=> Rails 3.1.3 application starting in development on http://0.0.0.0:3000
=> Call with -d to detach
=> Ctrl-C to shutdown server
[2012-02-24 17:20:01] INFO WEBrick 1.3.1

Which is what I would expect. After switching to Rails 3.2.1, if I do
the following:

rails plugin new blank_engine_test --mountable
cd blank_engine_test/
rails s

Usage: rails COMMAND [ARGS]

The common rails commands available for engines are:
generate Generate new code (short-cut alias: "g")
destroy Undo code generated with "generate" (short-cut alias:
"d")

All commands can be run with -h for more information.

The command "rails -h" produces the same thing thing.

If it helps I'm using rvm on OS X.7 and Ruby 1.9.3p0.