Respectfully...
Several people have asked why a malicious act has not been mentioned - much - as a possible cause.
First, because the only hint of it was a single bomb threat - against a different flight - in a different city - two countries and 1000nm away - 3 days earlier.
Second, because there was a clear and obvious threat to the flight from the tropical storm line across the planned, reported and airway-defined flight route - and close to the wreckage site.
If someone walks into busy traffic and falls down dead, the general response will be to try and figure out which vehicle hit him - not look for a possible sniper on a surrounding building. What are the odds?
Third, because there is not much that pilots can do, outside of barring the cockpit door, against terrorism or a bomb that got through security. A pilots' forum is naturally going to focus on the things within their speciality and experience that could go wrong and could be fixed in future. Procedures, skills, planning, equipment, and aircraft design.
@PJ2: I'm not sure why you are so doubtful about the route of flight as plotted against the weather charts. It was the route planned, it followed an airway, it was confirmed en route by the aircraft reporting INTOL and expecting TASIL in 50 minutes, on that airway, and the wreckage is fairly consistent with an extension of the line INTOL/TASIL, allowing for wind and other drift. It is possible that the aircraft diverted, or even turned around. But there is no evidence of it, and the other evidence is in favor of the plane following the route as planned. Best evidence rules.
On the subject of lightning, yes, The Weather Channel did check 2 lightning plotting networks which both recorded no strikes near the AF447 presumed flight path. At the same time the meteorologist also said that lighting bolts can follow CB anvils up to eighty miles horizontally (in his experience) - and that the networks occasionally miss strikes. So it is absence of evidence, not evidence of absence. Not persuasive either way.