Sony sold an impressive 500,000 PlayStation 2 units over the Christmas period, the platform holder has announced.It pointed to "emerging countries and regions such as Eastern Europe, the Middle East, Southeast Asia and South America" as the main markets for the decade-old warhorse.Anyone care to hazard a guess at how many new GameCubes or original Xboxes were snapped up over the same period?The PlayStation 3 sold 3.9 million units worldwide between 21st November 2011 and 5th January 2012, while the PSP managed 1.6 million.As reported earlier today, the Vita racked up half a million sales in its first month on shelves in Japan.Finally, the PlayStation Move peripheral sold 1.7 million units worldwide.Sony's announcement added that the PlayStation 3 remains on track to meet its target of 15 million sales for the current fiscal year, which ends on 31st March.