If you are wondering what happened to the "select all" option in BBM for broadcast messages, it was torn out of BlackBerry 10. In early builds it was there. But for some reason it has been omitted in recent BlackBerry 10 OS releases. However, it looks that by demand, it will be coming back in OS 10.1. A recent demo video posted by BerryWD, shows off the feature being used on the BlackBerry Q10 smartphone.
Check out the full demo video below (in Arabic) of the BlackBerry Q10 demo: