It needs to say 3 instead of W or people will not have a clue as to what it means. You might also try a 1/4 size D imposed onto the bottom right of the 3.
Or you could leave the W for wallpaper (because that is what your product is) and then have a 3D emblem or banner at the top in small clean font or on a gold emblem or star like how some have the HD indicated on their icons.
Actually scratch my last post. The new black and blue one looks good. Try lighting the bottom of the 3 a little so it stands out more when it's scaled down.
Thanks for your comments skins, we still need to do a little more finising touches, simple is usually the way to go, but there are also many other successful icons that are quite busy when you look at them more closely