Sharing segments is easy in Discover. Although a little too easy. The downside is that from an Admin's perspective, sharing segments in Discover, pushes them out to ALL SiteCatalyst users. This can cause massive confusion and bad data, especially if users are basing decisions off segments that have been setup wrong.
Admin's are not able to see what users setup the segments in Discover, which makes it even tougher to manage.
Solution - allow admin's to manage global/shared segments that get pushed out to SiteCatalyst. This should be built into the SiteCatalyst UI admin section, similar to how admins control which global calculated metrics are shared across all users.
Next up, Calculated Metrics. No option to share calculated metrics in Discover, which means on governance. Unlike SiteCatalyst that allows this, Discover does not.
I've read there are big changes coming for Calculated Metrics. These should be shared across ALL Adobe products that let you pull in Calculated Metrics.
Solution - create a global method to create and share calculuated metrics across Adobe products.