Then would someone mind telling me WHY this is being treated as 9/11 - part II? (Just kidding. I think I know why…)

TSA: Terrorists may be conducting dry runs

Security officers alerted to possibility of airport attack after seizures

July 25: Airport security officers have been alerted to watch for terrorists doing dry runs for possible attacks.

WASHINGTON - Airport security officers around the nation have been alerted by federal officials to look out for terrorists practicing to carry explosive components onto aircraft, based on four curious seizures at airports since last September.
[...]

It [bulletin] cited various types of rehearsals conducted by terrorists before the Sept. 11, 2001, attacks on the World Trade Center and the Pentagon; the July 7, 2005, London subway bombings; the Aug. 2, 2006, London-based plot to blow up trans-Atlantic flights using liquid explosives and the 1994 Bojinka plot in the Philippines to blow up multiple airliners over the Pacific Ocean.
[...]

The four seizures were described this way:

   * San Diego, July 7. A U.S. person - either a citizen or a foreigner legally here - checked baggage containing two ice packs covered in duct tape. The ice packs had clay inside them rather than the normal blue gel.
   * Milwaukee, June 4. A U.S. person’s carryon baggage contained wire coil wrapped around a possible initiator, an electrical switch, batteries, three tubes and two blocks of cheese. The bulletin said block cheese has a consistency similar to some explosives.
   * Houston, Nov. 8, 2006. A U.S. person’s checked baggage contained a plastic bag with a 9-volt battery, wires, a block of brown clay-like minerals and pipes.
   * Baltimore, Sept. 16, 2006. A couple’s checked baggage contained a plastic bag with a block of processed cheese taped to another plastic bag holding a cellular phone charger.

Read the TSA government advisory (.pdf)
Full article at MSNBC.com