Right now, the UUA tries to be everything to everyone. We should determine what's most important, most central to our faith, and jettison the rest. Realistically, doing so would take years of study and introspection - but taking a 'slimming down' as the goal, we could turn the UUA into an organization more focused on the core principles and needs of our faith.
If there is still strong support for certain non-core functions - social justice comes to mind - those functions could be spun off into a separate organization. UUA member congregations could then choose whether or not to join those organizations independently of their choice to affiliate themselves with the UUA. This would enhance congregational polity.