Ok, this is running all over the web, but I thought I’d better say that if you read further in this article, there is a spoiler. It tells you what the ‘extra bonus’ is if you manage to complete the game on the ‘Legendary’ difficulty setting. You have been warned!
Basically, after completing the game on the highest difficulty setting, there appears an extra line at the very bottom of the credits, stating simply: ?Coming February 9th?. Freaky huh? Feb 9th 2005? 2006? Halo 3? Extra levels? Who can say? Those crafty devils over at Bungie eh?