Hmm, overall I think this wallpaper has a lot of potential, I love the scan you are using and the way you've set up the colors.

My suggestions for improvement would be to take out the two borders at the top and the bottom, the background sand could be made more realistically proportion, make it smaller so it seems as if Gaara is standing IN the desert, not ontop of it. You can try adding a horizon in the background as well, but thats your choice. I would suggest removing the drop shadow from Gaara as well.

The writing on the left is good but make it a little smaller with less red, it would look good that way.

Good job otherwise, keep up the good work =)