World of Warcraft came out in North America on November 23 2004 (Europe had to wait until February 11 2005), which means in about a week we'll have to stop using the catchy phrase "ten-year-old game" and throw in a couple of extra syllables. It does means extra goodies for WoW players though.
Blizzard plans to celebrate the occasion for two weeks, with a special achievement—the snappily named WoW's 11th Anniversary achievement—and an Anniversary Gift Package available to those who log in between now and the end of the month.
That gift package contains the following items:
If you want to really show your appreciation for the game, there's a hashtag (because of course there is) with which to do so: #11YearsofWoW. Check it out for lots of stories of people who've met their significant others through the game. Aww.