If you are already subscribed to be notified of new posts, you will need to re-subscribe using the new method.
In two weeks (or whenever I get around to doing it), I will delete the database section for all current subscriptions registered with the old form (the one that was in the sidebar). If you do not re-subscribe, you will no longer receive notifications. Basically I am switching from a non-WP plugin form to one that is a plugin and easier to manage spam (yes, the bastids get me that way, too).
As always, if you have any difficulties with either process, just let me know.