Here is a first stab for a draft proposal to organize our volunteer testing activities:
http://www.mediawiki.org/wiki/Talk:QA/Strategy#Manual_testing_strategy
Written after some lousy discussions with Chris and Sumana, and reading a bunch of related wiki pages. Your feedback is welcome.
Ideally this _theory_ will be immediately applicable to some pilots that we can run in the upcoming weeks. The Language and Mobile teams seem to be ready for a try - maybe even before the end of the year. Visual Editor and Editor Engagement teams might come next in January.
The door is open for any other project willing to run QA activities with volunteers. Just let me know.