This investigation is, of course, parallel and separate from the National Civil Aviation authorities as well as authorities from other countries invited ...and is geared towards finding criminal behaviours on any of the parties involved, but it's the investigation with the highest rank of authority, so it's the first one any evidence etc needs to be presented to.
Well if there are mechanical issues look for Service Bulletins or AD's from the US in the near furture.
Anything else, don't hold your breath for at least a year or two.