This rumor has been going around for a while and it seems that now Nikon confirmed it (according to a ProLost reader who received this email from Nikon):
“We are working on an update to these equipments to allow manual selection of shutter speeds and ISO during D-Movie mode and more, we don’t have a specific date but we are working on it. We have had customers with the same concern and we are trying to improve on this firmware update.”
Via ProLost