No Daedric creatures, as they do not apply to Nehrim lore.
A number of unique bosses that can be encountered in most explorable dungeons, mines, etc.
Some animals drop elements that can be obtained only if you have appropriate Hunting Skill.
Unlike in Oblivion, people and main characters are full of emotions and act spontaneously, just like human being do.
You will have definitely more companions to accompany you on your travels or help you with some missions than in Oblivion.
Maybe a secret admirer will accompany you... :)
The areas in Nehrim are far more varied than in Oblivion, Actually, in Nehrim you have three main realms: The Middlrealm (capital: Erothin), The Northrealm (capital: Cahbaet ), The Southrealm (capital: Ostian)
Only a few main cities, but they are really huge and impressive.
You cannot have a house in every city.
Dangerous Dungeon are unique explorable places that are really challenging.
A list of places can be found here. Each place is unique.
There are a variety of services offered in Nehrim ranging from simple skill upgrade (which requires money as well as learning points) to taking a bath or depositing some money in a bank account.