I think loot system could copy a few of the new ideas in destiny, like lowered chance of having multiples of same unique item drop.
Collections of weapon blueprints instead of everything being inventory managed, this also gives some form to the completionist grind that we're already in. And sorts some issues with the you-need-this-to-get-that connections.
Could have variations on this new hidden list requirement thing without feeling too off-putting, like a chain of several drops that needs to happen in order. Veterans would get them faster since all older items are suppressed already.
Multiple weapons could have guaranteed higher damage number on next drop, until max and then it wouldn't drop, or chance would be a tenth or whatever works best for the economy.
Platinum would work better as well if you could at least feel that every other chest lowered the chance of seeing an unwanted item again.
You might get returning players dropping some platinum when new items were added, cause they know everything else is suppressed.
I think the dragon loot table was great and made the community better, do more, get some of this new stuff decent droprates on specific hb and nm runs. Like 27 dagger 5% in hb ruins for instance. Any way i could get the dagger without being horribly bored would be great really.