Solo dungeons are getting an adjustment with their challenges now becoming more difficult. This will arrive in increased levels and modified stats. For example Outlaw Arena will now have a recommended level of 60 HM 18 and higher, and recommended Attack Power of 1675 and higher.
Additionally, taking down specific NPCs in these dungeons will result in new supply chest drops. These chests will contain mats which are generally found in raids and heroic dungeons. A new fishing zone called Silverfrost Fishing Grounds has opened up as well.
A new Legendary PvE bracelet is added as well. This is a class-specific Sanctum Bracelet which can evolve into Storm Rage, Wild Rage, or Thunder Rage bracelets entirely dependent on your preference in class spec.
You can check out the full list of system changes and item additions here.