Destiny dev diary is all about armor, weapons, and loot

Destiny is all about exploration — going back out into the stars to recover everything that humanity lost after the collapse of the Golden Age. 

“The more you defeat your enemies and complete your missions, you’re going to earn rewards that will let you upgrade your Guardian in every conceivable way," says Bungie community manager David "DeeJ" Dague.

Adding to the topic, Bungie design lead Lars Bakken explains, "One of the ways we let you customize yourself is through the way you project yourself into the world in your armor, and we have a really neat progression from base player armor — which is pretty simple — to the really exotic stuff that you get by playing the end game content like raids or high level strikes."

Elsewhere, the video covers Destiny's private loot system and the three weapon system (primary, special, and heavy).