How can I remove the "Dash Home" icon from the Unity launcher?

I wasn't satisfied with the answers so I compared the 11.10 Unity-2D source with earlier versions. It can be done. Here's how to do it:

(for 11.04/11.10)

gksudo gedit /usr/share/unity-2d/launcher/Launcher.qml

(for 12.04)

gksudo gedit /usr/share/unity-2d/shell/launcher/Launcher.qml

Scroll down until you find the following section:

    Component.onCompleted: {
        items.appendModel(bfbModel);
        items.appendModel(applications);
        items.appendModel(workspaces);
        items.appendModel(devices);
        shelfItems.appendModel(trashes);
    }

items.appendModel(bfbModel); is the offending line of code. Remove this line (or comment it out). Save your changes and close the file.

Restart Unity-2D with:

killall unity-2d-launcher

(12.04)

killall unity-2d-shell

Let's hope someone adds a way to toggle this feature in the upcoming Unity settings manager. Cheers!