We need a way to share tests in a central place.
One possibility would be a directory in the SVN repository for TikiWiki. The advantage is that it's already under revision control. The disadvantage is that non-dev users may not know how to commit stuff to SVN. In fact, they may not even have an SVN client installed.
Maybe non-dev testers can simply email their tests to a dev and he will check them into SVN.
Another option would be for TikiTests to have some mechanism for exporting a particular test to SVN. But then, TikiTest might have to implement version management functionalities, for example, to allow the user to merge changes made to a particular test, inside TikiTest. Could turn into a complicated project.