ergonimics!
AdamWill:
I point out that there's lots of ways to do all those things that are more efficient even than clicking on a panel. You can switch workspace with ctrl-alt-up or ctrl-alt-down.
So to change desktop all i need to do is :
put down my coffee, let go of my mouse, take my eyes off the screen to look at the keyboard, press ctrl and alt with my left hand, press up (or down) with my right, look back at the screen to check I'm on the right desktop, repeat as necessary and finally go back to the mouse and pick up my coffee.
How much more efficient that is than the old-fashioned way of "move mouse two or three inches, click on icon in desktop switcher applet, continue working"
With the old-fashioned way, you never even got the chance to look away from the screen!