If the Heathrow plotters did the same—and some argue that a plot as sophisticated and complex as this one would demand such outside expertise, we could be seeing some "re-networking" of a jihadist movement that had been viewed as atomized in the post-9/11 period. That would both raise the danger level—because more technical expertise could be brought to bear in a conspiracy—and increase the chances of intelligence services catching wind of an operation. The more moving parts there are, and the less insulated a cell is, the easier it is to find.
Suicide attacks: When Ramzi and Khalid Sheikh Mohammed planned Bojinka, the expectation was that the bomber would get on a flight at its point of origin, assemble the bomb on board, and get off at another stop before the plane began the long leg across the Pacific. (When Ramzi did his test run on the Philippine Airlines flight, he boarded a plane to Tokyo in Manila and got off, after taping the bomb under a seat, on the Philippine island of Cebu.) We don't know yet if the Heathrow attacks were planned as "martyrdom operations," but if the targeted flights went directly from Heathrow to the United States, then they were probably intended to be suicide bombings.
That, in turn, would confirm that there are more individuals with greater emotional commitment—fanaticism, if you prefer—available for jihadist terror than before. That may not be big news, but it is a depressing reminder of how the phenomenon has deepened and become more threatening in a very short time.