They needs some colory glow in the background around the objects, the black make it look bad. wc3 icons are usually filled with color, if its just an object they add a glow around it to fill it up. Wich WILL make it look better.
No approval yet, i'd appriciate it if you could "fix" them.
Most your icons are really nice, but one thing you need to do (don't know if you already know this) I've used 2 of your icons so far, and both had a black Alpha channel, making them... well.. black :D Remember to make your alpha channels white :)