Hi there,

I am testing the Stretch testing weekly and I am amazed, it is so smooth and fast on the same machine I was running LMDE2, since it is testing I know things will be broken, my question is, when the official release become available do I need to do anything, now some apps can not be installed due to some flaw in the software source setting prevented me to change repository, and since it is still in testing, I don't know if I need to manually change the repository source at later time, or the system will take care of it, I love Debian because of the 'rolling release' design, so I will always get updated without too much of intervention.

The entry in /etc/apt/sources.list needs to use the release name of the actual testing to use it as the stable release (once it is released).
That is: if you have "testing" in the sources list, it will stay to be debian-testing, after the release of stretch.
You can now change it to "stretch" or after the release change it to "stable".
But if you want to run testing all the time, you want "testing" in your sources list.

I am clear now, thanks !