January 2009 was the first time Al Qaeda in Yemen had the capacity to plan, resource, and execute global operations. If this is true, I think its reasonable to ask why did it take nearly 12 months before their first strike? It's important for us to continually remind ourselves that Al Qaeda has extremely long planning horizons. Osama bin Laden declared war on the United States six months prior to the embassy bombings in Tanzania and Nairobi. AQAP became increasingly open with their activities in Yemen. Bill Roggio of the LWJ covers this aspect, and explains AQAP's openness was the primary reason for Ali Abdullah Saleh's recent raids. Since the Dec 17 attack involved US cruise missiles, AQAP probably felt the need to quickly retaliate to save face. From an IO perspective, their failed operation was far more successful than the US cruise missiles. If FLT 253 was a retaliatory act, it shows a remarkable capability on AQAP's ability to plan and execute an attack in only one week.
I think we often don't give enough credit to our enemy's capabilities. I believe its obvious that Umar Farouq Abdulmutallab completed his radicalization and suicide training prior to the Joint Dec 17 strikes. I am not 100% familiar with Al Qaeda suicide training, but I don't believe that AQAP could talk Abdulmutallab into Martyrdom in only a few days. One theory I have, Abdulmutallab was supposed to be one of the suicide bombers planning to attack the British Embassy in Yemen, which was the reason for the Dec 17 strikes. Another possibility, AQAP had the Christmas Day attack planned prior to the Dec 17 attacks. The timing alone is brilliant; the President is on vacation, hundreds of thousands of travelers would be stranded with a stand down of air travel, and the blow that the stranded workers/wallstreet would inflict on our economy would be significant.
It is far to early for effective analysis on the paticular Christmas Day attack, but it is blatantly clear that AQAP is now a global threat.