I've been logging into my dashboard, and it says: "Some of your subscriptions are about to expire! Visit the Upgrades page to renew them." It then lists:
Domain Mapping April 18, 2008 Upgrade
Domain Registration April 18, 2008 Upgrade
However, in the "domains" page, in the line "Your blog URL," under expires, it says "April 17, 2009 (Renew)"
I'm not sure why there are two different expiration dates, if someone could explain.