Google TV shortcuts

General Google TV Shortcuts
Reboots the Google TV device: Ctrl + R + Backspace
Switches tasks: Alt + Tab
Use the arrow keys to navigate among or close tasks: Long Hold Home Views open tasks

If you use your Google TV with a regular wireless keyboard and mouse, there are the key mappings to be from a normal keyboard to the Sony remote:
Windows Key: Search
Home: Zoom in
End: Zoom out
F1: TV, Guide or DVR
F2: Home
F3: Back
F4: Menu
F6: TV in window
F7: TV or Guide or DVR
F8: TV or Guide or DVR
F12: 'Star button', add bookmark, subscription, etc.