<p>I ruined several unit tests some time ago when I went through and refactored them to make them more <a href="http://en.wikipedia.org/wiki/Don%27t_repeat_yourself" rel="noreferrer">DRY</a>--the intent of each test was no longer clear.  It seems there is a trade-off between tests' readability and maintainability.  If I leave duplicated code in unit tests, they're more readable, but then if I change the <a href="http://en.wikipedia.org/wiki/System_Under_Test" rel="noreferrer">SUT</a>, I'll have to track down and change each copy of the duplicated code.</p>

<p>Do you agree that this trade-off exists?  If so, do you prefer your tests to be readable, or maintainable?</p>

Readability is more important for tests.  If a test fails, you want the problem to be obvious.  The developer shouldn't have to wade through a lot of heavily factored test code to determine exactly what failed.  You don't want your test code to become so complex that you need to write unit-test-tests.
However, eliminating duplication is usually a good thing, as long as it doesn't obscure anything, and eliminating the duplication in your tests may lead to a better API.  Just make sure you don't go past the point of diminishing returns.