Patch tests in issue queues? How does one get a patch tested in core and attached to an issue queue (with the pretty red or green styling)?  

Is it automatically done when you attach a patch? Or do you have to have an account to the qa.drupal.org server?
Patches uploaded on issues are automatically tested if they meet the right conditions which include:


not excluded based on name (described in description on upload field)
project has testing active
patch is again d6-8 banch


For core, testing is enabled; if you upload a patch against Drupal 7, for example, it will automatically be tested. For other projects, it can be enabled if you are a maintainer by looking at the "Issue" settings tab, there is a checkbox to enable testing.