New Classes Ninja and Kunoichi won't see a May release and have been pushed back "a little bit". It is safe to assume June/July or Fall 2016 at the latest for these classes I'd say. Apparently they need more balance tweaks even in Korea right now, and won't be introduced to NA/EU until after that.
Valencia region is set to release in June and this is the "Black Desert" region which is quite a bit larger than the Mediah update. It will be released in three stages.
Awakening Weapons are going to be introduced around the same time for all classes except Witch/Wizard at this time.
+20 enchantments are on their way as well, however Daum made it clear they want the NA/EU to include less of a gear disparity than Korea which they claimed is more "extreme". So they are working on how best to add this.
New Female Only Dark Elf Class is being developed, no word on a release and still no word on a male counterpart, but it is certainly a possibility.