Its exploitative of people's fears regarding terrorism, which is fine. If Kerry were to run an ad that was exploitative of people's fears (say images of vietnam interspersed with images of Iraq along with home movies of some of the soldiers that have died in Iraq), you Bush strokers would be frothing at the mouth.
Personally, I hope the dems do it. Better yet, show the same 9/11 footage, interspersed with the Bin Laden footage released post-9/11, and ask the question, "The man responsible for the death of 3000 Americans on 9/11 is still at large. Why did we not make him our number 1 priority in the war on terror?"
Wheeee! Whoever wins, this is going to be a hell of an entertaining election, heh.