Great analysis EH! I was thinking along those lines this morning.
>> a successful attack shortly after the "Night of Power" would be considered by many Muslims as a sign of Allah's approval <<
IIRC, 10/29/05 is the 'Night of Determination'. From what I've read, this is the night the mahdi would become known. Would be a good time for someone to claim they are this mahdi and give his 'blessing' for major attacks to begin.
I agree with you and brucew - now is not the time to relax.
I just read on some website today (sorry can't remember where) that the "night of power" as it was referred to was actually tonight. They stressed extra vigilance today, as well as the time period from Nov. 3 - 6 as that is the celebration time at the end of Ramadan.