At this time Memberships only serve to control access to web content by granting or restricting access to products, pages, etc.
What is missing is the capacity to interact with the members.
Sending email to the "membership" seems an essential function for anyone who sells events. There seem to be a core of essential functions that companies that do events, workshops, classes, etc., would use regularly and would be relatively easy to implement.
This would change memberships from a simple restrict content or give a discount to a much more powerful relational tool to communicate with members.
AdminPatrick Rauland (Admin, Automattic) commented
This would be better handled by Follow Up emails, or even better, an email service like MailChimp. The upcoming member export would let you work with MailChimp for this.