It's been two years since QA Checklist was created. Its contents haven't changed in that time, but best practices for developing for and deploying Drupal have.
Now that the module has a Drupal 7 version and is being actively maintained again, let's see if we can bring it up to date with the best, most thorough collection of best practices tasks and resources possible. I'd like to involve the community and build it collaboratively here. When it seems reasonably complete, I'll roll the result into a new release.
Redefine the groups and tasks. Each task should have an explanation and one or more links to supporting documentation or expanded instructions on Drupal.org. Special subsets of tests that won't apply to every site, such as for an ecommerce site, will be put in sub-modules that can be enabled separately to expand the list. (They won't be separate checklists; they'll add groups and tasks to the main one.) Make your suggestions in the comments. We'll wrap them into the summary as they're accepted/agreed-upon.