A memo sent to various Virgin Megastores in the UK may hold the key to the still undisclosed Nintendo Wii launchdate. The letter, supposedly sent by Nintendo UK's Head of Games, reveals that 10 stores will be receiving a "countdown" clock later today, which should give us a clearer picture of when the Wii is actually going to launch. Since this was sent to Viurgin Megastores specirfically, we assume other outlets around the UK most likely received the same notice, if this letter of course is legit and not somebody playing a sick joke with our Wiilings...