Posting out to the existing platforms ? yes it is a feature of Buddystream but the developer of Buddystream appears to be snowed under at the minute and is currently unable to give a level of support the plugin users need. Moreover it is a premium plugin.
The posting out feature does not appear to be covered in bebop but is covered (although not simultaneous with posting) by the BuddyPress Share It /BuddyShare by modemlooper who appears to be as supportive as anyone could wish for. Hopefully Facebook, linkedin etc will eventually be integrated into bebop. I just hope the heavyweights on this forum (volunteers etc)if they have the time, will give bebop a good look over and perhaps contribute ideas wise to help it on its way as (IMHO) it could be a major addition to buddypress.