Wow. If I remember right, I managed to fire off a note to Mason saying the 'real' problem is finding room to 'brand' the drawer in the same way that OS X and Windows are now branding folders... (Which should really be an OS service, etc, etc...)
These sure addressed that.

I'd love to see an isometric version for the heck of it, but definitely make a backup of them as they are! Especially those caution-striped ones...
Another thought is that (for the non-colorblind among us) it's probably important to preserve a standard color for drawer/folder-class icons that isn't used in other classes. Folders have the advantage of being "manilla;" drawers didn't matter so much in 4 colors, but now they're at a relative disadvantage, though the 3.5? isometric set did well there.
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Crazy, ridiculous, don't listen to me thought: What if Workbench grouped drawers into a 'filing cabinet' by default? Drawers down one side of the window, maybe with the option of a dividing line (vertical rule), objects of another type off to the right or left?