K2 Integration - By Items Submitted, Categories Managed, etc.

Deeper K2 integration would be nice.

For example,

1) create/sync a MailChimp list that includes everyone who has submitted a K2 item to any category, or to specific categories (Recipes vs. Books, for example)

Use Case: We want to email everyone who has submitted an item to the Hospitals category, to let them know we've added a few Extra Fields, and please come back and add this information.

2) create/sync a MC list of all Category Managers according to membership in a group named *Category Manager.

Any other creative ideas you come up with...