I may have spoke too soon. I got an email tonight that said my membership will be exporting on.12/31/12 and I'm eligible for a $29 extension promo price.
I made a purchase from a participating store and after it shipped, received an email saying, "You made a $50 purchase and qualify to renew for $29. Your current membership expires 12/31/2013." However, when I log-in, it tells me 03/19/2014 is the expiration date (12 months + 3 months for doing the Shoprunner Central thing and then cancelling it). I have a PDF printout of the 2014 expiration date and will try getting them to honor it should my account mysteriously close on 01/01/2013.