It read: "Finally we announce . . . The response to what happened in Mu'ajila - the killing of our women and our children from the Ba Kazim tribe - will be a catastrophe for the enemies of God, with the permission of God."
Mu'ajila (my voweling is a complete guess here) was the village in Abyan that the US attacked on December 17, 2009, killing a number of women and children. The exact numbers are disputed, and some officials claim that a handful of AQAP members were killed in the strike, but the Yemeni government later paid blood money to the tribe, acknowledging its mistake. (The payment was prior to news articles confirming US involvement in the raids.)
I have no idea, whether the parcel bomb plot was meant to be the "catastrophe" that AQAP warned of earlier this summer. More recent statements did not included the line, but when news of this broke it was one of the first things I thought about.
Just a note of reminder that in order to know what AQAP is thinking and planning it is important to read what they are producing - and I don't mean Inspire magazine.