An interim report on the missing Malaysian flight MH370 has been published - see Air Traffic Management 8th March 2015. Here is a direct link to the report issued by the Malaysian Ministry of Transport (585 pages pdf).
The report outlines how the investigation team is considering numerous areas, namely the the airworthiness and maintenance and aircraft systems of the Boeing 777-200ER aircraft registered 9M-MRO; air traffic controller operations from 1719 to 2232 UTC on March 7, 2014; cargo consignment; crew profiles, diversion from filed flight plan route and satellite communications.
Factual information gathered on MH370 include air traffic control radio and radar tape recordings; a review of aircraft maintenance records; simulator sessions to reconstruct the aircraft flight profile and systems operation; interviews with more than 120 persons; visits to cargo operators, freight-forwarders and consignees of lithium ion batteries and mangosteen fruit.
Please also see the earlier blog post and the various links therein - MH370