In Drupal core, we use issue thresholds to manage technical debt. Both critical (release-blocking) and major (non-release-blocking, high-impact issues) are considered. When we have more open issues than our thresholds, we do not commit new features.
Currently, we have 27 critical bugs, 41 critical tasks, 155 major bugs, and 149 major tasks. This is more than twice our current thresholds for critical issues, and about 50% more than our thresholds for major issues. We need your help to resolve these issues so that we can resume adding new features to Drupal 8. That would be a very exciting place to get to!
There are many ways to help, including not only programming but also updating these issues' summaries, testing the patches, and making sure the patches still apply. I encourage everyone to collaborate on major and critcal issues, and to consider making them a focus at the DrupalCon Portland sprints.
— Dries Buytaert