Investigations take a long time. They aren’t going to give weekly updates, but that doesn’t mean nothing is happening. They granted one of the techs who worked on it immunity. They don’t do that if nothing is happening. They grant immunity to the low level people to get evidence on bigger fish.
They got Petraeus back in yesterday (a SATURDAY) for another round of questions so you know they got more info and had to ask him to clarify details or straighten out discrepancies.