Till now I am used to use the Scott Hanselman's Watir controller for NUnit just to integrate results of Ruby Test::Unit tests to CruiseControl.NET. It does good with NUnit results. So if we can run Ruby tests with NUnit, we have nothing more to do.
However, it would be good too to do without intermediate unit-testing code, if only Test::Unit runners could store there result in form of some common XML
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