I think it would be a very welcomed asset to the game and would open possibilities for many awesome mods. [Currently All I know of for a Daedric Prince creature model is Antares Mehrunes Dagon, then there is Azura and Hircine.]
Unique creatures for Molag Bal, Boethiah, Vaermina, Sheogorath, Mephala, Meridia, Sanguine, Malacath, Nocturnal, Peryite, and Hermaeus Mora, and Clavicus Vile, would be amazing. Though, I personally only like Molag Bal, Sheogorath, and Sanguine.
Just a suggestion or thought.