So the two guys who were using stolen passports have been identified. They are both Iranians, and according to family members, they stole passports in order to get into Europe where they were going to seek asylum. It is possible that their families are covering for them, but a Malaysian jet carrying mostly Chinese citizens does not seem a likely target for Iranian terrorists. Most likely just a coincidence that they were on a flight that went down.
In other bizarre airline news, North Korea conducted an unannounced missile test that happened to come close to crossing paths with a Chinese passenger jet. That's pretty dumb on NK's part. If they piss off China, they pretty much cease to exist.