Guardians of the galaxy rejoice, Bungie have confirmed the forthcoming 1.12 update for Destiny will significantly increase your vault space.
“Today, the dimensions of your Vault provides for the storage of twenty (20) ARMOR pieces, twenty (20) WEAPONS, and twenty (20) GENERAL items – you know, things like materials, shaders, emblems, ships, vehicles, etc,” posted Bungie.
“Update 1.1.2 will push the boundaries of your secure repository. The new dimensions will let you store twenty-four (24) ARMOR pieces, thirty-six (36) WEAPONS, and twenty-four (24) GENERAL items.”

This means you will be able to store every exotic weapon, until The House of Wolves is released and more exotics coming in to play.
There is one small downside, due to the limited memory on the older consoles you will no longer be able to compare weapons on PlayStation 3 and Xbox 360.
Bungie have also stated that the suspend feature from yesterday’s 2.5 update for PS4 will not work with Destiny at present, this will be fixed in Destiny update 1.12.
Source: Bungie