There are a ton of new things. I will mention some of the bigger changes as I don't want to go into too much detail:
- The biggest thing is probably the orc race, which is why the update has been delayed. It comes with its unique ability and perks
- Combat rework - not a complete overhaul, but it has been changed severely
- Leveling rework - a new statistic, as well as a better level-up mechanic, has been implemented
- Minimap - a feature requested by many people
- Tons of new textures
- Some lore
That about rounds up the bigger stuff. There are, of course, more things that have been updated, but you will have to wait to see them.