BBM on BlackBerry 10 will  scan all of a users contacts and shows  which of the contacts have BBM.  Users will then be able  easily invite them to be on the BlackBerry 10 contact list.

The end product will be called  BBM Recommended contacts tab , yet it does not share the other users PIN but does allow invites.  There are quite  big changes coming to BlackBerry Messenger with BlackBerry 10, and BBM will maintain backwards compatibility with the current BBM builds on older phones.


 Source: BerryReview