Good news for the open source crowd.
Issue Tracker is the tool Google uses internally while building and maintaining all the various stuff it does. It's also the public facing bug tracker for many of its other products, including the Android O Developer Preview. The new system looks and feels very much like Google Groups, and Google says this makes it easier for everyone to be on the same page when it comes to finding and killing bugs.
We are hoping to facilitate a better collaboration between our developers and our Android product teams by using a tool we use internally at Google to track bugs and feature requests during product development.
Issue Tracker also uses standard Google terms of service, so be sure to read what you are agreeing to the first time you use the service.
For most end users this has zero impact. But know that the people developing Android and fixing the inevitable bugs should now be able to better communicate. Everything works better when everyone involved knows what's up.