Test Pilot is currently only a "still-in-concept platform," but the plan is to build a representative sample of Firefox users that will be recruited to evaluate new interface concepts and features.
As Mozilla points out in its 'vision' statement for Test Pilot, it's not just Firefox that could profit from a usability lab on this scale, but every Mozilla Labs project could benefit from this wide-scale testing of new ideas and interfaces. As Mozilla's Aza Raskin notes, most of the feedback that Mozilla currently receives is in the form of feedback from early adopters, anecdotes from users, and ad-hoc experiments.
How it Will Work
After the installation, the Test Pilot addon will gather non-personally-identifiable information from its users and then put these users into different demographic buckets. Depending on the tests that need to be run, users will be selected to participate in different experiments and will be asked to provide feedback on a regular basis. All the information gather through this plugin will be made available to the public.
This sounds like a great project, and we are happy to see that Mozilla is moving forward with this. It will probably still be a while before we see the fruits of this idea, however, as Mozilla is only now hiring a full-time developer to create the actual implementation of the Test Pilot program.