A: Typically with Windows 8, the desktop can easily be accessed from the Windows 8 Start Screen or with the WindowsKey+D keyboard combination. To switch to the desktop as part of a custom shortcut, use the following:
C:\Windows\explorer.exe shell:::{3080F90D-D7AD-11D9-BD98-0000947B0257}
This could be used in several scenarios to provide easy access to the desktop.
Some readers told me they are using it to automatically open to the desktop for certain types of test machines in Windows 8, such as triggering the shortcut when a logon event occurs via the Task Scheduler or just placing a shortcut file in the Startup folder (e.g., in folder C:\Users\<user name>\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup).
See also, "Q: What are the new keyboard shortcuts for Windows 8?" and "Windows 8 Keyboard and Mouse Survival Guide."