This will make every TDD/Groovy enthusiast happy: Groovy 1.7 will contain powerful assertions. This assertion here

assert new File('foo.bar') == new File('example.txt')

will yield this output:

Caught: Assertion failed:  assert new File('foo.bar') == new File('example.txt')        |                   |  |        foo.bar             |  example.txt                            false

Isn’t that cool?
Read more about the new Features in Groovy 1.7.