If we rule that the ray does not destroy armor with the person it's disintigrating we have a problem.
Are we saying that the ray can pass through substances (like armor) and only affect the creature that is targeted? If so, does this ranged touch attack then ignore cover as well, passing through it to hit the target? Either it passes through EVERYTHING except the target, or it passes through NOTHING, disintigrating the first thing it touches. Since the spell says nothing about dusting armor and not the wearer, I have to assume it will dust both, otherwise we have a ray that can go through things without effecting them.
IMC, I make it work like a Star Trek phasor set on disintigrate. The target, and everything it's wearing and holding, go *POOF*, leaving a fine trace of dust. Of course, then you have the problem that the raised PC has lost all his cool stuff, and the poofed NPCs don't provide the PCs with their cool stuff... Well, life sucks when you get hit with a 6th level spell. At least you get a save. I'd let a limited wish bring back the stuff though just 'cause I'm nice that way.