The Bungie team recently gathered a plethora of fan questions and have answered several of them on PlayStation.com. Topics range from whether or not there will be PvP to how many players can game together.
@jaydawg6958: How deep does the customization go? (Source)
DeeJ: All the way down to your bones! Well, maybe not that far, but Destiny will be what you make of it.
All of the weapons and gear you can earn in Destiny can be customized — some more than others, but the goal is to let every player tell a story through the gear and abilities they’ve earned and wear. You create a character, pick a class, gender, and race, and then you customize the way you look and fight by completing missions, defeating enemies, or maybe just by exploring the world.
Read more Destiny questions and answers.