There are three use cases I've identified that I feel would add value to Dashboards.
1. If I'm a user who creates a task, with a need for someone else to help - it'd be great to put a filter on a Widget where Author = Current User, Assignee = Not Current User (as a "Waiting For" Widget)
2. If I'm a manager who creates a task which I delegate to a team member, it'd be great to put a filter on a Widget where Author = Current User, Assignee = My Teams Excluding Current User (as a "Delegated" Widget)
3. Removing the Author = Current User filter, point 2 becomes a great "Watch List" for overseeing a team.
All of these could be easily accomplished per department with an "Assignee = Not Current User" Filter Option, and would really be helpful to track what tasks are in others' courts from Dashboard View.