I’ve noticed two interesting talks made at the FOSDEM recently about QA on the Debian project (well, second one, not especially focused on Debian, but Martin speaks from experience with the Debian project of course), whose slides, I think, are really worth reading :
- Nobody expects the Finnish Inquisition, or: confessions of a Debian package torturer, by Lars Wirzenius,
- and Quality Issues in Free Software Projects, by Martin Michlmayr (University of Cambridge, UK)
First one is probably more humoristic, although more technical 
In any case, there is surely room for much improvement on systematic Quality Assurance in Libre projects.
