If you have very interesting wallpaper background and wishing to have windows taskbar to be translucent then you need not to worry. Here is one such application able to do the task.

This is called Fading Taskbar; This is not able to fade the taskbar but also fades in and out with the movement of the mouse over it.

Features of FadingTaskbar:
•    Individual transparency settings for when the mouse is inside and outside the taskbar.
•    Fade in, fade out.
•    Makes the taskbar solid when maximized windows exist.
•    Remembers the original transparency.

Download Fade Taskbar