For other's info: Screen shot of the challenge cache

Assuming this stays, there are two major changes. The death breath, as you mentioned, will allow cubing of all 3 items.

The second is the blood shards. This will actually be an incredible change to how leveling up is done. 950 is far more than can be carried. This means, if you open up your cache, you'll be forced to roll to be able to carry them all. If you get lucky and get your necessary item early, Leoric's Signet seems the way to go to finish off the rest of the overflow shards, and when you hit 70, you'll have a full amount of shards once you hit 70. And it should cut down the odds of not getting the item you desire significantly.