The goal would be to lure experienced TDD devs in by focusing the event on testing, make them work with the community during a weekend on the code base, existing test, writing tests, etc. and mentor others along the way. (I'm still convinced that giving it a cool, flashy, name doesn't hurt ;-)
We might even have a nice cultural clash as a result:)
The recent discussion on this list about deprecation levels might indicate a a lack of DRY (Don't Repeat Yourself) in core code, and an opportunity to refactor for testability, with specific examples.