I like the idea of brand new elements, but Im of the opinion that our current three subclasses will be updated similarly to how our stasis abilities will be customizable. I feel like the way bungie'll go, in terms of updating our current elements, we'll get a new branch in each subclass tied to the darkness. Honestly, I'd be cool with that; new ways to play current subs with one new super across each, 3 for each guardian... Rather than a new element. I think I'd be fine with either, but prefer an interesting overhaul of what exists, with some new things to spice it up, rather than just one new element later down the line.