I haven't used it because I don't have that much of time.
I will try it later in summer vacation... 
Still I would like it to be capable of.......
Texture Brush or Fill.
Add, Place & Resize Cliparts.
Containers For Icons eg spheres, cubes, pyramids etc.
Anti-aliasing (at edges)
Some effects filters.. morph, border, glow, fill with shapes, snow, rain, lines, glitter etc...
Sorry If I am talking silly, I have no experience of creating icons...