Q. How can I list all devices that are capable of waking my machine from sleep?

A. Run

powercfg -devicequery wake_armed

to see all devices that are allowed to wake your machine. An example run of the command from my system is shown here.

C:\>powercfg -devicequery wake_armed
 Microsoft USB Dual Receiver Wireless Mouse (IntelliPoint)
 Realtek PCIe GBE Family Controller
 Microsoft USB Dual Receiver Wireless Keyboard (IntelliType Pro)