You might have received an announcement from Authorize about their upcoming upgrade.
If not you can read it here:
Rest assured that we have been preparing this upgrade for weeks.
We've elected not to charge your account for the development time required by these Authorize changes.
However, we will require your account to be charged for One (1) hour of professional services support at your usual webmaster agreement rates, and this for each website we host for you. During that time we will deploy the required upgrade, and perform tests to ensure that your store is operational and functioning normally post-update.
If your site is not currently hosted with us, minimal intervention charge time will apply.
We will keep you apprised as when we firm up our schedule for this operation and when it has been completed on your site(s).
Feel free to contact us with any questions and concerns.