BiGnAdAd, my $0.02:
I found that on WinMo 6.5.x, where the taskbar is slightly smaller in height that the squared off icons seem almost .. cluttered (for lack of a better term) and aren't really showing off the beauty of your work. I tried the purple ones myself on 6.5.5.
My suggestion, for what it's worth, would be to see how inverting the icons (not literally of course, hopefully this makes sense) so that the item is colored instead of black and removing the bounding box would look. Kinda more like your current set of speaker icons ... they're bold and pop nicely while still maintaining the hint of color and gradient backgrounds. Not really "dusk", I know, but I think they would look striking and clean on both a solid black and a wallpapered background.
I think your work is beautiful, just offering suggestions
