Here is the latest information from Tivo:
"Glad to know that Comcast is still keeping contact. We're working with them to supply any information or data they need from us, but at this time, we believe the root cause is something on their end, so there isn't anything TiVo can directly do to get it restored. We are supporting Comcast in any way we can.
I last heard from my contact late last week and he was still investigating the issue. I don't have an ETA, but I know both teams are focused on restoring functionality as soon as possible."