There were similar images after Hurricane Andrew, and that was responsible for all of 26 deaths directly (3 in the Bahamas) and 65 deaths total. Hurricane Hugo slammed Charleston head on as a Category 4, and killed 'merely' 57 people directly. I'm still quite skeptical of the notion that Katrina has killed at least 2000 people in Mississippi (to qualify as "thousands").
No point in speculating, but my guess is that many thousands died in this storm, when the final accounting is done. If I am wrong, nothing would delight me more.
I am with you..all the copters flying in basically unrestricted airspace would have surely seen "thousands" or even hundreds of dead bodies. Or the media would have picked radio traffic sqawking about about it on radios...naaaaaah, I ain't buying it.
I think the majority of the deatsh are undouns yet and will take weeks to find whcih may in turn be thousands of dead. I don't beleive they have been "found" yet.