A new paper has been published based on the Blackbox data: 37 Million Compilations:
Investigating Novice Programming Mistakes in Large-Scale Student Data
The paper was written by Amjad Altadmri and Neil Brown (both working in our group at the University of Kent).
You can find a full copy of the paper here.
(If you have any papers planned or published related to Blackbox, please tell us — we would like to mention them here.)