Unfortunately I missed JCertif last weekend. My visa was in Brazzaville but I couldn't board in a flight from Johannesburg to Congo without it. Max Bonbhel kindly tried to fax me the visa, but the last flight to Congo closed and I had to come back to Brazil sooner. :-(
Here is the slides that I was going to use there. Hope you take some time to read about TAP, SubUnit and other test protocols. There are two special points to pay attention to, one single format and extensibility.
With a single format for your test results, you won't need to write many different parsers, one for each distinct format. Extensibility refers to the fact that using formats like xUnit (like JUnit) or TestNG XML you are limited to the XML schema.
Many projects are aiming automation in different levels. Executing automated tests can lead to situations where you need to have information like the database used, JDK version, screen shots taken during some tests, exception stack traces, etc. TAP and SubUnit provide manners to extend your test result and inform to a test consumer (the tool that reads your test output) about such information.