This is the feature my friend and I would very like to use: we would be able to synchronize our timetables, organize time spent together. Therefore there would be ability to add a person's profile to the list of people who can see/edit the personal calendar.
Moreover, if there would be an incoming event that would be interesting for the group or community (like e.g. GSOC for dw_dev community:P ), this would not only notify about deadlines, but also help to organize the tasks, and be brief, clear and easy way to spread information.
So - more precisely - for every calendar there would be assigned a list of persons with defined rights. They could be added individually or within a group. (Of course, they could resign from being on that list). People with particular rights would be able to manage the calendar.
Group calendar events
Moreover, if there would be an incoming event that would be interesting for the group or community (like e.g. GSOC for dw_dev community:P ), this would not only notify about deadlines, but also help to organize the tasks, and be brief, clear and easy way to spread information.
So - more precisely - for every calendar there would be assigned a list of persons with defined rights. They could be added individually or within a group. (Of course, they could resign from being on that list). People with particular rights would be able to manage the calendar.
(Is this a satisfying answer? :P)