I used to use Magit <2's wazzup mode to survey unmerged branches or general branch divergence. What's the right way to do that or some other way to view unmerged branches in Magit 2?
v2.1 the "branch manager" and "wazzup" were merged into one mode. Such changes are usually being announced in the release notes.
The new Refs buffer combines the features of the old Wazzup and Branch Manager buffers into one, more powerful and efficient synthesis. For each reference, cherries can be shown by expanding the ref section, but unlike in the Wazzup buffer, the cherries are not calculated until the expansion happens, making it vastly more efficient. Besides local and remote branches, the buffer now also lists tags, and users can add additional sections listing other refs, e.g., stashes. The format of refs headers is now customizable.
The new key binding is y.
By default the number of commits a branch has in addition to those in the current branch are not shown, that would be to expensive when there exist many refs with many additional commits. You can show them using C-y, or you can customize