Update 12/29/2007: This is no longer a bug. It has been fixed since I originally posted this.
This is the second bug in Virtual Earth 6 that I've found today. It appears that the showSwitch parameter of the LoadMap method is broken and no longer works.
As the documentation states:
"A Boolean value that specifies whether to show the map mode switch on the dashboard control. Optional. Default is true (the switch is displayed)."
Below is a screenshot showing what is incorrectly happening and what should be happening: