Dry Run for Al-Qaeda?

Breaking:

Two suspicious packages were found on cargo flights overnight. All of the packages contained toner cartridge, powder, and wire, and were from Yemen.  Packages were found on UPS cargo planes in Philadelphia International Airport, Newark Airport, and on a UPS truck in Brooklyn.  The truck was searched and cleared.  A suspicious package was also discovered on a UPS cargo plane in London. A jet arriving at JFK Airport from the United Arab Emirates that was reported to have a similar package that originated from Yemen was accompanied by F-16 fighter jets and searched upon landing.

Was this a dry run for a terror attack?

UPDATE: 4:29pm President Obama addressed the nation minutes ago and stated the packages were en route to places of Jewish worship in the United States and that it appears as if the packages did indeed contain explosive devices.