Was looking at the sig link. :/ My bad.

Now that I see the correct one, let me critisize.
Wind filter; Lose it. It's one of the most useless filters in Photoshop right next to the evil Lens Flare. The only time it would be semi-relevent is if you made something to look like frozen icicles and snow. Anything else is wasted space and not pleasing to look at.
Lineart; I see 5 areas that either have a gap or a cheap cover-up. Anti-alias the lines if they're not already.
Background; Ah yes, the wonderful gradient tool. For Gods sake, use this thing called the Eraser Tool in some spots. There are 2 bright gradients going right that are completely not in alignment.
Top and bottom; Add more shit than black. Atleast my last wallpaper that had that is semi-transparent, so it isn't just pure black. Add text, too. No wallpaper is complete without text.

As you can see, you need to work on LOTS.