While developing Mocha, I have to admit I’ve been somewhat remiss in keeping up-to-date with the latest developments on projects like RSpec and FlexMock. It looks like both projects have gone further than Mocha with implementing the JMock concepts. FlexMock also now supports simple class interception (see FlexMock::TestCase#intercept), but it admits to being “very simple-minded”, has “a number of restrictions” and “a proxy class constant will be left behind”.
I don’t think Stubba suffers from these limitations, but I’ll save a more detailed explanation for another post. It doesn’t look like either project has anything like AutoMocha.