This is completely normal. If you use the device as intended, i.e. the other way up, you would never even hear this or notice it.
If the rest of your device works just fine and you got this rattling thing then it would not be smart to exchange it, you may end up with far worse troubles if you are unlucky.
/ Magnus
Strange. Because microsoft told me that this was NOT normal. I use the device as intended, and i hear and notice it on mine simply picking it up or putting it down.
If the kickstand rattles when you pick it up, then perhaps it's too loose. Mine only rattles when open at 150 or <~22 degrees. When I say rattles - I mean if I pick it up, there is no noise, not unless I shake my device vigorously, which is probably not the intended use of the machine.
In these areas, the kickstand has less friction and more room to move.
Mine makes a clack when i lift it up and put it down. At any angle. Microsoft confirmed that it was not normal. Yet for some reason user sfter user keeps telling me that despite this advice from microsoft, it is actually acting normally. It leads me to wonder how many of these people offering such advice are actually afflicted by this issue, and how many are simply making it up as they go along.