Should Rails include Mocha?

I like the way the Rails integration tests currently depend on Mocha.

# integration_test.rb
...
begin # rescue LoadError
require 'mocha'
...
rescue LoadError
  $stderr.puts "Skipping integration tests. `gem install mocha` and try again."
end

In fact, I stole the idea and changed it up a bit for sqldsl.

unless File.directory? File.dirname(__FILE__) + '/../vendor/mocha-0.4.0/'
  raise "mocha 4.0 is required to run the test suite. create the 'vendor' directory as
         a sibling of test and 'gem unpack mocha' in 'vendor'"
end
$:.unshift File.dirname(__FILE__) + '/../vendor/mocha-0.4.0/lib/'
require File.dirname(__FILE__) + '/../vendor/mocha-0.4.0/lib/mocha'

However, now I'm wondering if Rails should depend on, and include Mocha.

I've previously written that I think xUnit frameworks should include Mocks. Since Rails bakes in testing, I believe it should provide you with the full array of testing tools, including Mocks.

Thoughts?