Intellij offers basic but adequate integration with JUnit. Test classes are recognized automatically enabling a Right-click/Run Test menu option. No clever tricks, however, like generating test stubs for existing classes. All the better for it I feel, unless you are testing someone else's code from scratch. 

If textui is used to run tests stacktrace elements become clickable hyperlinks for jumping into the code when things go wrong. Although I miss the coloured bar I am afraid this is just too handy and I run all my tests in text mode now.
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Intellij 3 does have a nice file templates feature. I have set up ones for TestCase, TestCase Aggregator and TestSuite Aggregator. -- MilesDaffin
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See: 
*** http://www.junit.org
*** http://intellij.com/idea/