Summary: Test on oil slicks show that the oil was not air craft fuel. It is suspected that there were 2 terrorists in the plane, as "Two European names -- Christian Kozel, an Austrian, and Luigi Maraldi of Italy -- were listed on the passenger list, but neither man boarded the plane.", someone(perhaps terrorists) had used their passports to board the plane.
Conclusion: This was a serious blow to MAS, and the other people related to the incident that were affected by it. I believe that everyone is praying hard for the safety of the passengers on board that flight. This heightens the importance of national security for the prevention of such issues.