Blizzard Entertainment has announced that an extra 250,000 copies of popular MMORPG World of Warcraft will arrive in Europe on April 15, each containing a new 10-day free trial offer. More than 620,000 copies of WoW have been sold in Europe since the game launched on February 11. It was previously rumoured that Blizzard was restricting the number of games on sale to prevent server overload, something it was forced to do in the US