I was browsing though the Javascript in Gmail and found a few interesting phrases:
"Your Agenda for "
"No earlier events"
"No events on this day"
"No later events"

Code can be found here (view source): https://mail.google.com/mail/?view=page&name=js&ver=o7buclnse2rk

More interesting stuff:
"Sorry! Changing the organizer is not allowed.";

I sure hope they come up with better integration!

Exciting news!

Upon further inspection, it looks like the organizer is referring to the organizer of an event.

Maybe they are going to do what Yahoo did. Yahoo has a small calendar bar at the bottom of the inbox.