There is something deeply fishy about those numbers but of course, for the average Joe, there is no way to verify them. So, it makes a great story for Dell or whomever.

My company laptop? Oh, ya, well, you see, ahum. Remember that trip I went on last year? Well, ah, I was at the airport the requisit 3 hours ahead of time waiting for my flight. Just to fill in time I took out my laptop and I...

Can you show me the best spot in Europe where the same happens?
I need a couple of lappies for my kids :-)

Or is this only an American thing?

"To accomplish the first phase of this study, we conducted field research at 106 major airports in
46 states to determine the frequency of lost or missing laptops or notebooks at their locations."

errrrrrrrrm, the operative words should be lost or MISSING AND FOUND AGAIN BY OWNER, 
it could be in one journey an owner MISPLACED their laptop several times and did not actually LOSE it, indeed even if a laptop was actually LOST how many times over a period of TIME had said lappy been MISPLACED at DIFFERENT airports before the weed smokin exec whose short term memory banks had been temporarily erased finally lost it, how many were insurance scams, blah blah blah, so lets drop the 600,000 lappy left in airports nonsense plzzzzzzzzzz :O)

Given the delicate nature of Laptops, and the rather ham-fisted nature of airport luggage handlers, I would have thought any one with any common sense would be carrying the laptop as hand luggage.

So how on earth do they manage to loose it?!