Your comparisons to World War II are interesting, but maybe not truly valid. I suspect the V-E and V-J Day celebrations in this country would have been pretty muted if we learned that Adolph Hitler had been killed in a compound outside London -- in 1951.
The simple truth is that Osama bin Laden has been off the radar screen of most people -- including most people in government and even the U.S. military -- for years.
It is incongruent to compare Great Britain as our WWII ally to Pakistan as our WOT ally. You might compare the Pakistanis to the Russians, but not the Brits.