Just thought I would post my workaround. If anyone has a better idea, let me know..
To restate, after today, June 15, we no longer accept subscriptions for 2009 membership. Our group has an annual subscription. So, we are going to setup a subscription plan as follows:
Plan Name: 2010 Membership.
Validity duration: This year and Next year
If anyone signs as a new member, we will inform them that their membership actually does not start until Jan 1. Their expiry date will be Dec 31, 2010.
Then, on Jan 1, we will modify the plan and make it for "This year" only. People who sign up after the 1st will have an expiry date of Dec 31, 2010, which will be correct.
The other workaround, that I kinda don't like, is that now we don't really have a renewal option for 2009 members. Basically, 2009 members will have to subscribe to 2010 membership as an upgrade.