Emma Watson is going to voice Princess Pea in the new movie The Tale of Despereaux.  Robbie Coltrane is also going to be voicing a character. It is coming out later next year, I will post more details as they come. Here is the movie description:

The tale of three unlikely heroes – a misfit mouse who prefers reading books to eating them, an unhappy rat who schemes to leave the darkness of the dungeon, and a bumbling servant girl with cauliflower ears – whose fates are intertwined with that of the castle’s princess.

Thanks HPANA!