According to a post on the Destiny subreddit, Destiny will have a total of 11 crucible maps, 22 story mission, 6 Strikes, 4 exploration areas, and 1 raid. The missions, strikes and raid will all have multiple difficulty levels. The information was data mined through the Destiny companion app by Destinydb. Although at this point it is not confirmed whether there will be more content included when Destiny launches. Update: The DestinyDB developer has pointed out that this information appears to be dated June 30, 2014. It stands to reason that additions/changes have been, and will continue to be made up
