What's the point of a bomb that size? That's simply an example of working harder, not smarter. Not to mention the excessive risk that you're gonna expose the Herk crew to--those things can't exactly notch, beam or jink if ya know what I mean.
If you really need a blast of that size, it's time for a tactical nuke.
EDIT: having just read the CNN story, it now makes sense: "...military officials tell CNN that the MOAB is mainly conceived as a weapon employed for "psychological operations."
Eglin's over by Pensacola on the panhandle. This is a big brother to the Daisy Cutter FAE (Fuel Air Explosive) developed in Vietnam to clear foliage for helo LZ's...not to kill people. In Afghanistan, they were used in Tora Bora to kill those in cave complexes. Ya see, it instantly consumes all oxygen over the affected area. The concussion actually causes the most casualties.
I think this is a psychological weapon and also a quick way to burn up chem/bio weps.