From the About page…
CL2 makes it easy â€” even effortless â€” to keep track of all the events in your life and compare them to what your friends and family have going on in theirs. Weâ€™ve designed a calendar that works for you â€” helping you add events from email, friends, and other public calendars â€” so you donâ€™t have to spend all your time maintaining your schedule. CL2 even helps you discover new events you might be interested in.
Head over to TechCrunch for lots of screenshots.
UPDATE: Valleywag alleges a Yahoo employee is responsible for leaking the details of the Google calendar project.