Pardon our dust! We are pushing a patch live today. Players will be required to log in to Destiny again after returning to the title screen to install the patch. You should not be removed from any activities you are currently in.
Report: Destiny will have 22 Story missions, 11 Crucible maps, 6 Strikes, 4 Exploration areas, and 1 Raid at launch
Title says it all - from the Destiny blog