I hadn't really thought about it, to be honest.  Given that other libraries might need to mock or stub a method in a syntax-agnostic way (since users of said library might use either syntax), it'd be good to have an official public API for doing so.  I think we need the same thing for rspec-expectations, too.  (It has a similar problem).

How does something like this sound?

``` ruby
RSpec::Mocks.expect_message(object, :message).with("foo").and_return(5)
RSpec::Mocks.allow_message(object, :message).with("foo").and_return(5)
```