Roster 2.2 is in its finishing stages and the next week will be spent on locals and bugs.
There have been many changes in roster Plugins are up and running for some addons and any addon can use them if designed too.
Addons can be dependent on core or other addons
The RosterApi can now be used and on any pull for characters if config is set too this pulls all api data for a character so any addon can use them if needed buy the array var data['API']
Roster Auth users addon now updates user ranks on update so if you promote some one in game and update there roster access for you!
This and much more coming