With Patch 2.0.1, the only thing that changed about the current Hellfire Ring/Infernal Machine event is the drop rates. Both Keys and Organs now only drop in Torment I or above at the following rates:
Torment I: 25%
Torment II: 28%
Torment III: 33%
Torment IV: 38%
Torment V: 43%
Torment VI: 50%
Level 70 Hellfire rings confirmed
Once you level past 60, the Wardens will no longer drop the keys for the level 60 event. Once you reach level 70, they will begin dropping keys appropriate for the level 70 event. This allows players who choose not to upgrade to Reaper of Souls to be able to continue doing the level 60 event while those who do upgrade can progress through the new Infernal Machine event at 70.
The level 60 rings aren't being removed from the game, and you'll be able to craft any remaining keys you have into the appropriate Infernal Machine event and run the 60 event as before. Just bear in mind that level 60 Infernal Machines will spawn the level 60 bosses and cannot be used for the level 70 event.