Windows 8 has added few newer keyboard shortcuts, keeping the old ones intact.
WIN + Q for application search, WIN + W for settings search, WIN + F for files search, WIN + I for Settings charm, WIN + O for rotation lock, WIN + C to bring up simple Start menu and time/date, WIN + A or WIN + Space for switching keyboard layouts, WIN + SHIFT + C brings up the touch charms bar, WIN + Y to glance at your desktop, WIN + Z brings up the application bar.
It supports old shortcuts too – WIN + D activates desktop, WIN + R opens Run, WIN + L locks user, WIN + E opens Explorer.