You heard right: all tests in XP are automated to ensure that things that already work continue to work when changes occur. It also allows XP teams to proceed rapidly and confidently.
See some of the articles at
http://www.objectmentor.com for descriptions of how they do continuous integration and
testing.
Edit: Actually, the continuous integration article is at
http://www.thoughtworks.com (where Martin Fowler works as Chief Scientist) At any rate, objectmentor.com also has a lot of articles you might be interested in.
Junilu
[This message has been edited by JUNILU LACAR (edited November 09, 2001).]