Comment 3 for bug 472697

The switch-on-connect module is in Ubuntu/pulseaudio 12.04, but needs to be added to defaults.pa manually.

Without this module enabled/added, when connecting a bluetooth speaker, it gets automatically used for playback.
However, it is not bound correctly to the volume controls, and starts with a volume of 100%.
See bug 1008539 about this.

I am closing this bug here, because switch-on-connect is now in Ubuntu and even without it, the new device is being used by default.