Google recently announced an upcoming "winter cleaning," which will result in a minor change to the HillConnect calendar. The appointment slots feature is scheduled to be discontinued on Jan 4, 2013 and for users with personal Gmail accounts that sync with their mobile device, Google Sync is going to be discontinued on Jan 30.
While you can still create new reservable slots until Jan. 4, and already-created slots will continue working for one year, you will no longer be able to create new ones once the feature is discontinued.
For users with personal Gmail accounts that sync with their mobile device, Google Sync is going to be discontinued on Jan. 30, in favor of new sync methods (IMAP, CalDAV & CardDAV) and mobile apps. This only applies to new devices that haven't synced in the past, and personal accounts - HillConnect accounts and devices already configured for Google Sync are not impacted.
If you happen to receive a new phone or tablet for the holidays, you may want to reference the updated documentation here:
More information, and a handful of other little-used services that are being retired, can be found on the official Google blog: http://goo.gl/p6KX1