NTSB has issued a preliminary report that doesn't seem to add much to what is already known. They did not travel to the crash but the site was inspected by the FAA.
Local media appears to be fixated on the report that the helicopter "rotated" before crashing. There are numerous local rumors that the aircraft may have been hit by gunfire. And details of the incident that resulted in the chopper being sent to that site remain murky.
Houston Chronicle article on NTSB report.