Fitnesse (http://fitnesse.org) is a popular but proprietary, crufty, and generally get-in-your-way wiki wrapper around Cunningham & Mugridge's brilliant FIT/FitLibrary (http://www.cs.auckland.ac.nz/~rick/FitLibrary/). It's a useful tool but inferior in many ways to Trac - and running 2 wikis on one project isn't a good idea.
An integration of Trac with FIT/FitLibrary would seize Fitnesse users bigtime and capture critical mindshare among testers and PMs in general.
The hack would probably just grab Trac's existing table format as html and stuff it into the FitLibrary? for testing and consequent colouring.
FitServers? exist for C#, Java, and Python. Testing tickets should have a property enabling tests to be directed to a particular FitServer?, and there would be a settable default for this.