I just added the photopass upgrade to an annual pass this evening. I called the photopass hotline this afternoon and they gave me quite a bit of good info, but had no ability to add the entitlement to my pass, directed me to contact DVC to add the options since I purchased the pass via DVC. After calling DVC and waiting there and being put on hold a few times (they couldn't handle this request either), they directed me to call central ticketing or wait until arrival and upgrade at guest relations.
I called central ticketing around 8PM central and did not speak to someone until 9:50! Once I had the correct person, it was a breeze.
In hindsight, I would have added the photopass option when I purchased the passes had I know it would take so much time and effort to get this handled!