Well, the details are vague so far, but they have mentioned that you will be able to sacrifice old gear (and mentioned several times for people not to dismantle it yet) to make new gear more effective... does this mean just damage? a chance to transfer perks? Who knows... But that would make much of the old gear relevant... imagine a new armor, and you fuse a VoG and Crota piece, so you get perks that help in both? Or even all new perks when they combine? [spoiler]...to be honest, it probably isn't gonna be that cool, but one can hope...[/spoiler]