what i think their concept for amd is to use the screw to tighten that hold the center bar, that fix the cooler position and to create a pressure so that the back plate will hold stick closely to mobo, which mean if u didn't install the megashadow yet, the bracket itself will goyang.
and i'm not very trust to the bracket, even it didn't scratch the mobo and make any component fall from mobo, but i'm afraik this metal plate above the mobo will touch with some component.
if this happened, short circuit is the result, and mobo will go goreng goreng...

here is the sample of one amd mobo, take a look around the cpu socket
http://www.jetway.com.tw/pic/big/HA07-Ultra.jpg
too many small component.

if anyone still wanna try his luck, might be the concept is right, it will hold the cooler nicely.
but be careful during installation.
I would prefer to use something looks more safety, let's say true.